bluuebunny/crossref_metadata_2025 huggingface dataset:
A Novel Enzyme-Based SPR Strategy for Detection of the Antimicrobial Agent Chlorophene
Authors: Quintanilla-Villanueva Gabriela Elizabeth , Luna-Moreno Donato , Blanco-Gámez Edgar Allan , Rodríguez-Delgado José Manuel , Villarreal-Chiu Juan Francisco , Rodríguez-Delgado Melissa Marlene
Published: February 2021

Chlorophene is an important antimicrobial agent present in disinfectant products which has been related to health and environmental effects, and its detection has been limited to chromatographic techniques. Thus, there is a lack of research that attempts to develop new analytical tools, such as biosensors, that address the detection of this emerging pollutant. Therefore, a new biosensor for the direct detection of chlorophene in real water is presented, based on surface plasmon resonance (SPR) and using a laccase enzyme as a recognition element. The biosensor chip was obtained by covalent immobilization of the laccase on a gold-coated surface through carbodiimide esters. The analytical parameters accomplished resulted in a limit of detection and quantification of 0.33 mg/L and 1.10 mg/L, respectively, fulfilling the concentrations that have already been detected in environmental samples. During the natural river’s measurements, no significant matrix effects were observed, obtaining a recovery percentage of 109.21% ± 7.08, which suggested that the method was suitable for the fast and straightforward analysis of this contaminant. Finally, the SPR measurements were validated with an HPLC method, which demonstrated no significant difference in terms of precision and accuracy, leading to the conclusion that the biosensor reflects its potential as an alternative analytical tool for the monitoring of chlorophene in aquatic environments.
Early Regulatory Skills and Social Communication Development in Infants with Down Syndrome
Authors: Schworer Emily K. , Fidler Deborah J. , Daunhauer Lisa A.
Published: February 2021

Children with Down syndrome (DS) demonstrate substantial variability in communication and language outcomes. One potential source of variability in this skill area may be early regulatory function. Characterizing the early link between regulatory function and early social communication may benefit infants with DS at risk of difficulties with social communication and language skill acquisition. Forty-three infants with DS were assessed at two time points, six months apart. At Time 1, the average chronological age was 9.0 months (SD = 3.9) and caregivers completed the Infant Behavior Questionnaire-Revised (IBQ-R) to assess regulatory function. Six months later, caregivers rated infant communication at the second visit using the Communication and Symbolic Behavior Scales Infant Toddler Checklist (CSBS-ITC). Infant developmental level was assessed at both visits using the Bayley Scales of Infant and Toddler Development, Third Edition and caregivers reported on developmental history and biomedical comorbidities. Infant regulatory function at Time 1 predicted social communication outcomes at Time 2, six months later. Findings from this study suggest that elevated risk for pronounced communication challenges may be detectable as early as infancy in DS.
Targeting and Reprograming Cancer-Associated Fibroblasts and the Tumor Microenvironment in Pancreatic Cancer
Authors: Sunami Yoshiaki , Böker Viktoria , Kleeff Jörg
Published: February 2021

Pancreatic cancer is the fourth leading cause of cancer deaths in the United States both in female and male, and is projected to become the second deadliest cancer by 2030. The overall five-year survival rate remains at around 10%. Pancreatic cancer exhibits a remarkable resistance to established therapeutic options such as chemotherapy and radiotherapy, due to dense stromal tumor microenvironment. Cancer-associated fibroblasts are the major stromal cell type and source of extracellular matrix proteins shaping a physical and metabolic barrier thereby reducing therapeutic efficacy. Targeting cancer-associated fibroblasts has been considered a promising therapeutic strategy. However, depleting cancer-associated fibroblasts may also have tumor-promoting effects due to their functional heterogeneity. Several subtypes of cancer-associated fibroblasts have been suggested to exhibit tumor-restraining function. This review article summarizes recent preclinical and clinical investigations addressing pancreatic cancer therapy through targeting specific subtypes of cancer-associated fibroblasts, deprogramming activated fibroblasts, administration of mesenchymal stem cells, as well as reprogramming tumor-promoting cancer-associated fibroblasts to tumor-restraining cancer-associated fibroblasts. Further, inter-cellular mediators between cancer-associated fibroblasts and the surrounding tissue microenvironment are discussed. It is important to increase our understanding of cancer-associated fibroblast heterogeneity and the tumor microenvironment for more specific and personalized therapies for pancreatic cancer patients in the future.
EphA2 and EGFR: Friends in Life, Partners in Crime. Can EphA2 Be a Predictive Biomarker of Response to Anti-EGFR Agents?
Authors: Cioce Mario , Fazio Vito Michele
Published: February 2021

The Eph receptors represent the largest group among Receptor Tyrosine kinase (RTK) families. The Eph/ephrin signaling axis plays center stage during development, and the deep perturbation of signaling consequent to its dysregulation in cancer reveals the multiplicity and complexity underlying its function. In the last decades, they have emerged as key players in solid tumors, including colorectal cancer (CRC); however, what causes EphA2 to switch between tumor-suppressive and tumor-promoting function is still an active theater of investigation. This review summarizes the recent advances in understanding EphA2 function in cancer, with detail on the molecular determinants of the oncogene-tumor suppressor switch function of EphA2. We describe tumor context-specific examples of EphA2 signaling and the emerging role EphA2 plays in supporting cancer—stem—cell-like populations and overcoming therapy-induced stress. In such a frame, we detail the interaction of the EphA2 and EGFR pathway in solid tumors, including colorectal cancer. We discuss the contribution of the EphA2 oncogenic signaling to the resistance to EGFR blocking agents, including cetuximab and TKIs.
Prognostic Value of the Hemoglobin/Red Cell Distribution Width Ratio in Resected Lung Adenocarcinoma
Authors: Petrella Francesco , Casiraghi Monica , Radice Davide , Cara Andrea , Maffeis Gabriele , Prisciandaro Elena , Rizzo Stefania , Spaggiari Lorenzo
Published: February 2021

Background: The ratio of hemoglobin to red cell distribution width (HRR) has been described as an effective prognostic factor in several types of cancer. The aim of this study was to investigate the prognostic role of preoperative HRR in resected-lung-adenocarcinoma patients. Methods: We enrolled 342 consecutive patients. Age, sex, surgical resection, adjuvant treatments, pathological stage, preoperative hemoglobin, red cell distribution width, and their ratio were recorded for each patient. Results: Mean age was 66 years (SD: 9.0). There were 163 females (47.1%); 169 patients (49.4%) had tumors at stage I, 71 (20.8%) at stage II, and 102 (29.8%) at stage III. In total, 318 patients (93.0%) underwent lobectomy, and 24 (7.0%) pneumonectomy. Disease-free survival multivariable analysis disclosed an increased hazard ratio (HR) of relapse for preoperative HRR lower than 1.01 (HR = 2.20, 95%CI: (1.30–3.72), p = 0.004), as well as for N1 single-node (HR = 2.55, 95%CI: (1.33–4.90), p = 0.005) and multiple-level lymph node involvement compared to N0 for both N1 (HR = 9.16, 95%CI:(3.65–23.0), p < 0.001) and N2 (HR = 10.5, 95%CI:(3.44–32.2, p < 0.001). Conclusion: Pre-operative HRR is an effective prognostic factor of disease-free survival in resected-lung-adenocarcinoma patients, together with the level of pathologic node involvement.
Prognostic Significance of Metabolic Parameters by 18F-FDG PET/CT in Thymic Epithelial Tumors
Authors: Lee Joohee , Cho Young Seok , Kim Jhingook , Shim Young Mog , Lee Kyung-Han , Choi Joon Young
Published: February 2021

Background: Imaging tumor FDG avidity could complement prognostic implication in thymic epithelial tumors. We thus investigated the prognostic value of volume-based 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/CT parameters in thymic epithelial tumors with other clinical prognostic factors. Methods: This is a retrospective study that included 83 patients who were diagnosed with thymic epithelial tumors and underwent pretreatment 18F-FDG PET/CT. PET parameters, including maximum and average standardized uptake values (SUVmax, SUVavg), metabolic tumor volume (MTV), and total lesion glycolysis (TLG), were measured with a threshold of SUV 2.5. Univariate and multivariate analysis of PET parameters and clinicopathologic variables for time-to-progression was performed by using a Cox proportional hazard regression model. Results: There were 21 low-risk thymomas (25.3%), 27 high-risk thymomas (32.5%), and 35 thymic carcinomas (42.2%). Recurrence or disease progression occurred in 24 patients (28.9%). On univariate analysis, Masaoka stage (p < 0.001); histologic types (p = 0.009); treatment modality (p = 0.001); and SUVmax, SUVavg, MTV, and TLG (all p < 0.001) were significant prognostic factors. SUVavg (p < 0.001) and Masaoka stage (p = 0.001) were independent prognostic factors on multivariate analysis. Conclusion: SUVavg and Masaoka stage are independent prognostic factors in thymic epithelial tumors.
Tailoring Properties of Metal-Free Catalysts for the Highly Efficient Desulfurization of Sour Gases under Harsh Conditions
Authors: Duong-Viet Cuong , Nhut Jean-Mario , Truong-Huu Tri , Tuci Giulia , Nguyen-Dinh Lam , Pham Charlotte , Giambastiani Giuliano , Pham-Huu Cuong
Published: February 2021

Carbon-based nanomaterials, particularly in the form of N-doped networks, are receiving the attention of the catalysis community as effective metal-free systems for a relatively wide range of industrially relevant transformations. Among them, they have drawn attention as highly valuable and durable catalysts for the selective hydrogen sulfide oxidation to elemental sulfur in the treatment of natural gas. In this contribution, we report the outstanding performance of N-C/SiC based composites obtained by the surface coating of a non-oxide ceramic with a mesoporous N-doped carbon phase, starting from commercially available and cheap food-grade components. Our study points out on the importance of controlling the chemical and morphological properties of the N-C phase to get more effective and robust catalysts suitable to operate H2S removal from sour (acid) gases under severe desulfurization conditions (high GHSVs and concentrations of aromatics as sour gas stream contaminants). We firstly discuss the optimization of the SiC impregnation/thermal treatment sequences for the N-C phase growth as well as on the role of aromatic contaminants in concentrations as high as 4 vol.% on the catalyst performance and its stability on run. A long-term desulfurization process (up to 720 h), in the presence of intermittent toluene rates (as aromatic contaminant) and variable operative temperatures, has been used to validate the excellent performance of our optimized N-C2/SiC catalyst as well as to rationalize its unique stability and coke-resistance on run.
Cell Line Models for Acquired Resistance to First-Line Osimertinib in Lung Cancers—Applications and Limitations
Authors: Ohara Shuta , Suda Kenichi , Mitsudomi Tetsuya
Published: February 2021

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) are first-line drugs for lung cancers with activating EGFR mutations. Although first- and second-generation EGFR-TKIs were standard first-line treatments, acquired resistance (AR) to these drugs is almost inevitable. Cell line models have been widely used to explore the molecular mechanisms of AR to first- and second-generation EGFR-TKIs. Many research groups, including ours, have established AR cell lines that harbor the EGFR T790M secondary mutation, MET gene amplification, or epithelial–mesenchymal transition (EMT) features, which are all found in clinical specimens obtained from TKI-refractory lesions. Currently, many oncologists prescribe osimertinib, a third-generation EGFR-TKI that can overcome T790M-mediated resistance, as a first-line TKI. Although few clinical data are available about AR mechanisms that arise when osimertinib is used as a first-line therapy, many research groups have established cell lines with AR to osimertinib and have reported on their AR mechanisms. In this review, we summarize the findings on AR mechanisms against first-line osimertinib obtained from analyses of cell line models.
Tat-Endophilin A1 Fusion Protein Protects Neurons from Ischemic Damage in the Gerbil Hippocampus: A Possible Mechanism of Lipid Peroxidation and Neuroinflammation Mitigation as Well as Synaptic Plasticity
Authors: Jung Hyo Young , Kwon Hyun Jung , Kim Woosuk , Hwang In Koo , Choi Goang-Min , Chang In Bok , Kim Dae Won , Moon Seung Myung
Published: February 2021

The present study explored the effects of endophilin A1 (SH3GL2) against oxidative damage brought about by H2O2 in HT22 cells and ischemic damage induced upon transient forebrain ischemia in gerbils. Tat-SH3GL2 and its control protein (Control-SH3GL2) were synthesized to deliver it to the cells by penetrating the cell membrane and blood–brain barrier. Tat-SH3GL2, but not Control-SH3GL2, could be delivered into HT22 cells in a concentration- and time-dependent manner and the hippocampus 8 h after treatment in gerbils. Tat-SH3GL2 was stably present in HT22 cells and degraded with time, by 36 h post treatment. Pre-incubation with Tat-SH3GL2, but not Control-SH3GL2, significantly ameliorated H2O2-induced cell death, DNA fragmentation, and reactive oxygen species formation. SH3GL2 immunoreactivity was decreased in the gerbil hippocampal CA1 region with time after ischemia, but it was maintained in the other regions after ischemia. Tat-SH3GL2 treatment in gerbils appreciably improved ischemia-induced hyperactivity 1 day after ischemia and the percentage of NeuN-immunoreactive surviving cells increased 4 days after ischemia. In addition, Tat-SH3GL2 treatment in gerbils alleviated the increase in lipid peroxidation as assessed by the levels of malondialdehyde and 8-iso-prostaglandin F2α and in pro-inflammatory cytokines such as tumor necrosis factor-α, interleukin-1β, and interleukin-6; while the reduction of protein levels in markers for synaptic plasticity, such as postsynaptic density 95, synaptophysin, and synaptosome associated protein 25 after transient forebrain ischemia was also observed. These results suggest that Tat-SH3GL2 protects neurons from oxidative and ischemic damage by reducing lipid peroxidation and inflammation and improving synaptic plasticity after ischemia.
Protein Kinase A-Mediated Septin7 Phosphorylation Disrupts Septin Filaments and Ciliogenesis
Authors: Wang Han-Yu , Lin Chun-Hsiang , Shen Yi-Ru , Chen Ting-Yu , Wang Chia-Yih , Kuo Pao-Lin
Published: February 2021

Septins are GTP-binding proteins that form heteromeric filaments for proper cell growth and migration. Among the septins, septin7 (SEPT7) is an important component of all septin filaments. Here we show that protein kinase A (PKA) phosphorylates SEPT7 at Thr197, thus disrupting septin filament dynamics and ciliogenesis. The Thr197 residue of SEPT7, a PKA phosphorylating site, was conserved among different species. Treatment with cAMP or overexpression of PKA catalytic subunit (PKACA2) induced SEPT7 phosphorylation, followed by disruption of septin filament formation. Constitutive phosphorylation of SEPT7 at Thr197 reduced SEPT7‒SEPT7 interaction, but did not affect SEPT7‒SEPT6‒SEPT2 or SEPT4 interaction. Moreover, we noted that SEPT7 interacted with PKACA2 via its GTP-binding domain. Furthermore, PKA-mediated SEPT7 phosphorylation disrupted primary cilia formation. Thus, our data uncover the novel biological function of SEPT7 phosphorylation in septin filament polymerization and primary cilia formation.
Comparative Mapping of the Macrochromosomes of Eight Avian Species Provides Further Insight into Their Phylogenetic Relationships and Avian Karyotype Evolution
Authors: Kiazim Lucas G. , O’Connor Rebecca E. , Larkin Denis M. , Romanov Michael N. , Narushin Valery G. , Brazhnik Evgeni A. , Griffin Darren K.
Published: February 2021

Avian genomes typically consist of ~10 pairs of macro- and ~30 pairs of microchromosomes. While inter-chromosomally, a pattern emerges of very little change (with notable exceptions) throughout evolution, intrachromosomal changes remain relatively poorly studied. To rectify this, here we use a pan-avian universally hybridising set of 74 chicken bacterial artificial chromosome (BAC) probes on the macrochromosomes of eight bird species: common blackbird, Atlantic canary, Eurasian woodcock, helmeted guinea fowl, houbara bustard, mallard duck, and rock dove. A combination of molecular cytogenetic, bioinformatics, and mathematical analyses allowed the building of comparative cytogenetic maps, reconstruction of a putative Neognathae ancestor, and assessment of chromosome rearrangement patterns and phylogenetic relationships in the studied neognath lineages. We observe that, as with our previous studies, chicken appears to have the karyotype most similar to the ancestor; however, previous reports of an increased rate of intrachromosomal change in Passeriformes (songbirds) appear not to be the case in our dataset. The use of this universally hybridizing probe set is applicable not only for the re-tracing of avian karyotype evolution but, potentially, for reconstructing genome assemblies.
Reduced Operation Current of Oxygen-Doped ZrN Based Resistive Switching Memory Devices Fabricated by the Radio Frequency Sputtering Method
Authors: Jung Jinsu , Bae Dongjoo , Kim Sungho , Kim Hee-Dong
Published: February 2021

In this work, we report the feasibility of resistive switching (RS) properties of oxygen-doped zirconium nitride (O-doped ZrN) films with platinum (Pt) and platinum silicide (PtSi) bottom electrode (BE), produced by a sputtering method. Compared to O-doped ZrN using Pt BE, when Pt/p-Si was used as BE, the foaming voltage slightly increased, but the operation current was reduced by about two orders. In particular, the average reset current of the O-doped ZrN memory cells was reduced to 50 µA, which can delay deterioration of the element, and reduces power consumption. Therefore, the use of PtSi as the BE of the O-doped ZrN films is considered highly effective in improving reliability through reduction of operating current of the memory cells.
Modeling of Poly(methylmethacrylate) Viscous Thin Films by Spin-Coating
Authors: Chapman Navid , Chapman Mingyu , Euler William B.
Published: February 2021

A predictive film thickness model based on an accepted equation of state is applied to the spin-coating of sub-micron poly(methylmethacrylate) viscous thin films from toluene. Concentration effects on density and dynamic viscosity of the spin-coating solution are closely examined. The film thickness model is calibrated with a system-specific film drying rate and was observed to scale with the square root of spin speed. Process mapping is used to generate a three-dimensional design space for the control of film thickness.
Low-Fluorine Ba-Deficient Solutions for High-Performance Superconducting YBCO Films
Authors: Ternero Pau , Alcalà Jordi , Piperno Laura , Pop Cornelia , Ricart Susagna , Mestres Narcis , Obradors Xavier , Puig Teresa , Sotgiu Giovanni , Celentano Giuseppe , Palau Anna
Published: February 2021

High-performing superconducting YBa2Cu3O7–x (YBCO) films are fabricated by a chemical solution deposition methodology through novel barium-deficient low-fluorine solutions. The precursor solutions, distinguished for being straightforward, inexpensive and eco-friendly, allow us to reduce the growing temperature of YBCO down to 750 °C. We investigated the influence of the growing temperatures on both the microstructure and superconducting properties of YBCO films by using conventional thermal annealing and flash-heating approaches. A clear correlation between the growing temperature (Tg) and the superconducting performance of the films was obtained with improved performances observed at low Tg.
Combined Use of Surface Texturing, Plasma Nitriding and DLC Coating on Tool Steel
Authors: dos Santos de Almeida Elisangela Aparecida , Milan Julio Cesar Giubilei , da Costa César Edil , Binder Cristiano , de Mello José Daniel Biasoli , Costa Henara Lillian
Published: February 2021

In cold rolling, a textured roll can be used to imprint a desired surface topography onto the sheet during rolling. This work proposes the use of diamond-like carbon (DLC) coatings to protect the surface topography of the rolls in replacement of the carcinogenic hard chrome. For that, hydrogenated amorphous carbon (a-C:H) was deposited on plasma nitrided tool steel, both for ground and textured specimens. Changes in surface topography due to DLC coating were assessed using a confocal microscope. Coating adhesion was evaluated using the method VDI 3198. The specimens were characterized using X-ray diffraction (XRD), microhardness test and scanning electron microscopy (SEM). The coating was characterized using Raman spectroscopy (RS) and X-ray photoelectron spectroscopy (XPS). The results showed a soft multilayer coating consisting of a plasma nitrided layer for load support, a Si-rich interlayer to improve adhesion and an a-C:H top layer. DLC deposition reduced the roughness of the textured specimens. The coating resulted in relatively stable friction and good durability, with small damage and negligible wear even under dry sliding.
Effects of Human Disturbance on Terrestrial Apex Predators
Authors: Ordiz Andrés , Aronsson Malin , Persson Jens , Støen Ole-Gunnar , Swenson Jon E. , Kindberg Jonas
Published: February 2021

The effects of human disturbance spread over virtually all ecosystems and ecological communities on Earth. In this review, we focus on the effects of human disturbance on terrestrial apex predators. We summarize their ecological role in nature and how they respond to different sources of human disturbance. Apex predators control their prey and smaller predators numerically and via behavioral changes to avoid predation risk, which in turn can affect lower trophic levels. Crucially, reducing population numbers and triggering behavioral responses are also the effects that human disturbance causes to apex predators, which may in turn influence their ecological role. Some populations continue to be at the brink of extinction, but others are partially recovering former ranges, via natural recolonization and through reintroductions. Carnivore recovery is both good news for conservation and a challenge for management, particularly when recovery occurs in human-dominated landscapes. Therefore, we conclude by discussing several management considerations that, adapted to local contexts, may favor the recovery of apex predator populations and their ecological functions in nature.
Quantitative Evaluation of COVID-19 Pneumonia Lung Extension by Specific Software and Correlation with Patient Clinical Outcome
Authors: Annoni Andrea Daniele , Conte Edoardo , Mancini Maria Elisabetta , Gigante Carlo , Agalbato Cecilia , Formenti Alberto , Muscogiuri Giuseppe , Mushtaq Saima , Guglielmo Marco , Baggiano Andrea , Bonomi Alice , Pepi Mauro , Pontone Gianluca , Andreini Daniele
Published: February 2021

Lung infection named as COVID-19 is an infectious disease caused by the most recently discovered coronavirus 2 (SARS-CoV-2). CT (computed tomography) has been shown to have good sensitivity in comparison with RT-PCR, particularly in early stages. However, CT findings appear to not always be related to a certain clinical severity. The aim of this study is to evaluate a correlation between the percentage of lung parenchyma volume involved with COVID-19 infection (compared to the total lung volume) at baseline diagnosis and correlated to the patient’s clinical course (need for ventilator assistance and or death). All patients with suspected COVID-19 lung disease referred to our imaging department for Chest CT from 24 February to 6 April 2020were included in the study. Specific CT features were assessed including the amount of high attenuation areas (HAA) related to lung infection. HAA, defined as the percentage of lung parenchyma above a predefined threshold of −650 (HAA%, HAA/total lung volume), was automatically calculated using a dedicated segmentation software. Lung volumes and CT findings were correlated with patient’s clinical course. Logistic regressions were performed to assess the predictive value of clinical, inflammatory and CT parameters for the defined outcome. In the overall population we found an average infected lung volume of 31.4 ± 26.3% while in the subgroup of patients who needed ventilator assistance and who died as well as the patients who died without receiving ventilator assistance the volume of infected lung was significantly higher 41.4 ± 28.5 and 72.7 ± 36.2 (p < 0.001). In logistic regression analysis best predictors for ventilation and death were the presence of air bronchogram (p = 0.006), crazy paving (p = 0.007), peripheral distribution (p < 0.001), age (p = 0.002), fever at admission (p = 0.007), dyspnea (p = 0.002) and cardiovascular comorbidities (p < 0.001). In multivariable analysis, quantitative CT parameters and features added incremental predictive value beyond a model with only clinical parameters (area under the curve, 0.78 vs. 0.74, p = 0.02). Our study demonstrates that quantitative evaluation of lung volume involved by COVID-19 pneumonia helps to predict patient’s clinical course.
Infinite Ergodic Walks in Finite Connected Undirected Graphs
Authors: Volchenkov Dimitri
Published: February 2021

The micro-canonical, canonical, and grand canonical ensembles of walks defined in finite connected undirected graphs are considered in the thermodynamic limit of infinite walk length. As infinitely long paths are extremely sensitive to structural irregularities and defects, their properties are used to describe the degree of structural imbalance, anisotropy, and navigability in finite graphs. For the first time, we introduce entropic force and pressure describing the effect of graph defects on mobility patterns associated with the very long walks in finite graphs; navigation in graphs and navigability to the nodes by the different types of ergodic walks; as well as node’s fugacity in the course of prospective network expansion or shrinking.
Estimation for Entropy and Parameters of Generalized Bilal Distribution under Adaptive Type II Progressive Hybrid Censoring Scheme
Authors: Shi Xiaolin , Shi Yimin , Zhou Kuang
Published: February 2021

Entropy measures the uncertainty associated with a random variable. It has important applications in cybernetics, probability theory, astrophysics, life sciences and other fields. Recently, many authors focused on the estimation of entropy with different life distributions. However, the estimation of entropy for the generalized Bilal (GB) distribution has not yet been involved. In this paper, we consider the estimation of the entropy and the parameters with GB distribution based on adaptive Type-II progressive hybrid censored data. Maximum likelihood estimation of the entropy and the parameters are obtained using the Newton–Raphson iteration method. Bayesian estimations under different loss functions are provided with the help of Lindley’s approximation. The approximate confidence interval and the Bayesian credible interval of the parameters and entropy are obtained by using the delta and Markov chain Monte Carlo (MCMC) methods, respectively. Monte Carlo simulation studies are carried out to observe the performances of the different point and interval estimations. Finally, a real data set has been analyzed for illustrative purposes.
Teachers and Teacher Education: Limitations and Possibilities of Attaining SDG 4 in South Africa
Authors: Nakidien Toyer , Singh Marcina , Sayed Yusuf
Published: February 2021

As we enter the last ten years leading to the realisation of the Sustainable Development Goals in 2030, African countries are still plagued with poverty and underdevelopment. For most children in Africa, the attainment of Sustainable Development Goal (SDG) 4 will remain elusive. Drawing from two interrelated empirical studies, one focusing on citizenship and social cohesion at high school level and the other on the implementation of assessment for learning at primary school level, it was found that not only are schools not equipped to provide the quality education as set out in SDG 4, but teachers need additional training to give expression to the ideals of SDG 4. In order for this to be adequately addressed, all interested stakeholders—government, business, and NGOs—need to be involved.
Reduction of Losses and Operating Costs in Distribution Networks Using a Genetic Algorithm and Mathematical Optimization
Authors: Riaño Fabio Edison , Cruz Jonathan Felipe , Montoya Oscar Danilo , Chamorro Harold R. , Alvarado-Barrios Lazaro
Published: February 2021

This study deals with the minimization of the operational and investment cost in the distribution and operation of the power flow considering the installation of fixed-step capacitor banks. This issue is represented by a nonlinear mixed-integer programming mathematical model which is solved by applying the Chu and Beasley genetic algorithm (CBGA). While this algorithm is a classical method for resolving this type of optimization problem, the solutions found using this approach are better than those reported in the literature using metaheuristic techniques and the General Algebraic Modeling System (GAMS). In addition, the time required for the CBGA to get results was reduced to a few seconds to make it a more robust, efficient, and capable tool for distribution system analysis. Finally, the computational sources used in this study were developed in the MATLAB programming environment by implementing test feeders composed of 10, 33, and 69 nodes with radial and meshed configurations.
State Management for Cloud-Native Applications
Authors: Szalay Márk , Mátray Péter , Toka László
Published: February 2021

The stateless cloud-native design improves the elasticity and reliability of applications running in the cloud. The design decouples the life-cycle of application states from that of application instances; states are written to and read from cloud databases, and deployed close to the application code to ensure low latency bounds on state access. However, the scalability of applications brings the well-known limitations of distributed databases, in which the states are stored. In this paper, we propose a full-fledged state layer that supports the stateless cloud application design. In order to minimize the inter-host communication due to state externalization, we propose, on the one hand, a system design jointly with a data placement algorithm that places functions’ states across the hosts of a data center. On the other hand, we design a dynamic replication module that decides the proper number of copies for each state to ensure a sweet spot in short state-access time and low network traffic. We evaluate the proposed methods across realistic scenarios. We show that our solution yields state-access delays close to the optimal, and ensures fast replica placement decisions in large-scale settings.
Deep Feature-Level Sensor Fusion Using Skip Connections for Real-Time Object Detection in Autonomous Driving
Authors: John Vijay , Mita Seiichi
Published: February 2021

Object detection is an important perception task in autonomous driving and advanced driver assistance systems. The visible camera is widely used for perception, but its performance is limited by illumination and environmental variations. For robust vision-based perception, we propose a deep learning framework for effective sensor fusion of the visible camera with complementary sensors. A feature-level sensor fusion technique, using skip connection, is proposed for the sensor fusion of the visible camera with the millimeter-wave radar and the thermal camera. The two networks are called the RV-Net and the TV-Net, respectively. These networks have two input branches and one output branch. The input branches contain separate branches for the individual sensor feature extraction, which are then fused in the output perception branch using skip connections. The RVNet and the TVNet simultaneously perform sensor-specific feature extraction, feature-level fusion and object detection within an end-to-end framework. The proposed networks are validated with baseline algorithms on public datasets. The results obtained show that the feature-level sensor fusion is better than baseline early and late fusion frameworks.
EnCNN-UPMWS: Waste Classification by a CNN Ensemble Using the UPM Weighting Strategy
Authors: Zheng Hua , Gu Yu
Published: February 2021

The accurate and effective classification of household solid waste (HSW) is an indispensable component in the current procedure of waste disposal. In this paper, a novel ensemble learning model called EnCNN-UPMWS, which is based on convolutional neural networks (CNNs) and an unequal precision measurement weighting strategy (UPMWS), is proposed for the classification of HSW via waste images. First, three state-of-the-art CNNs, namely GoogLeNet, ResNet-50, and MobileNetV2, are used as ingredient classifiers to separately predict and obtain three predicted probability vectors, which are significant elements that affect the prediction performance by providing complementary information about the patterns to be classified. Then, the UPMWS is introduced to determine the weight coefficients of the ensemble models. The actual one-hot encoding labels of the validation set and the predicted probability vectors from the CNN ensemble are creatively used to calculate the weights for each classifier during the training phase, which can bring the aggregated prediction vector closer to the target label and improve the performance of the ensemble model. The proposed model was applied to two datasets, namely TrashNet (an open-access dataset) and FourTrash, which was constructed by collecting a total of 47,332 common HSW images containing four types of waste (wet waste, recyclables, harmful waste, and dry waste). The experimental results demonstrate the effectiveness of the proposed method in terms of its accuracy and F1-scores. Moreover, it was found that the UPMWS can simply and effectively enhance the performance of the ensemble learning model, and has potential applications in similar tasks of classification via ensemble learning.
Rock Pillar Design Using a Masonry Equivalent Numerical Model
Authors: Moffat Ricardo , Caceres Cristian , Tapia Eugenia
Published: February 2021

In underground mining, the design of rock pillars is of crucial importance as these are structures that allow safe mining by maintaining the stability of the surrounding excavations. Pillar design is often a complex task, as it involves estimating the loads at depths and the strength of the rock mass fabric, which depend on the intact strength of the rock and the shape of the pillar in terms of the aspect ratio (width/height). The design also depends on the number, persistence, orientation, and strength of the discontinuities with respect to the orientation and magnitude of the stresses present. Solutions to this engineering problem are based on one or more of the following approaches: empirical design methods, practical experience, and/or numerical modeling. Based on the similarities between masonry structures and rock mass characteristics, an equivalent approach is proposed as the one commonly used in masonry but applied to rock pillar design. Numerical models using different geometric configurations and state of stresses are carried out using a finite difference numerical approach with an adapted masonry model applied to rocks. The results show the capability of the numerical approach to replicate common types of pillar failure modes and stability thresholds as those observed in practice.
The Efficiency of a Fence of Tidal Turbines in the Alderney Race: Comparison between Analytical and Numerical Models
Authors: Thiébot Jérôme , Djama Dirieh Nasteho , Guillou Sylvain , Guillou Nicolas
Published: February 2021

Assessing the efficiency of a tidal turbine array is necessary for adequate device positioning and the reliable evaluation of annual energy production. Array efficiency depends on hydrodynamic characteristics, operating conditions, and blockage effects, and is commonly evaluated by relying on analytical models or more complex numerical simulations. By applying the conservations of mass, momentum, and energy in an idealized flow field, analytical models derive formulations of turbines’ thrust and power as a function of the induction factor (change in the current velocity induced by turbines). This simplified approach also gives a preliminary characterization of the influence of blockage on array efficiency. Numerical models with turbines represented as actuator disks also enable the assessment of the efficiency of a tidal array. We compare here these two approaches, considering the numerical model as a reference as it includes more physics than the analytical models. The actuator disk approach is applied to the three-dimensional model Telemac3D in realistic flow conditions and for different operating scenarios. Reference results are compared to those obtained from three analytical models that permit the investigation of the flow within tidal farm integrating or excluding processes such as the deformation of the free surface or the effects of global blockage. The comparison is applied to the deployment of a fence of turbines in the Alderney Race (macro-tidal conditions of the English Channel, northwest European shelf). Efficiency estimates are found to vary significantly from one model to another. The main result is that analytical models predict lower efficiency as they fail to approach realistically the flow structure in the vicinity of turbines, especially because they neglect the three-dimensional effects and turbulent mixing. This finding implies that the tidal energy yield potential could be larger than previously estimated (with analytical models).
A Model for Multiple Hydraulic Fracture Propagation with Thermo-Hydro-Mechanical Coupling Effects
Authors: Sun Tianwei , Zeng Qingdong , Xing Huilin
Published: February 2021

In this study, a coupled thermo-hydro-mechanical model to simulate multiple hydraulic fracture propagation is presented. Fracture propagation with elastic deformation is described by using a displacement discontinuity method. The temperature distribution and induced thermal stress are calculated via a semi-analytical method in an explicit way. An iterative scheme is proposed to solve the coupling between fracture propagation with fluid flow and induced thermal stress. The numerical model is validated against related analytical solutions. Several numerical cases are modeled to investigate the controlling factors for uniform growth of multiple fractures. Results show that using non-uniform fracture spacings and proper increasing the spacing for fractures away from the heel of wellbore promote the uniform growth of multiple fractures by comparison with using uniform fracture spacings. Increasing the perforation diameter for the middle cluster also works. Besides, single-wing fracturing could greatly improve the uniform growth of multiple hydraulic fractures. Finally, it shows that the thermal stress has a significant influence on fracture geometrical size but has limited effect on fracture propagation path. In addition, the thermal effect promotes the uniform growth of multiple fractures.
Efficiency Improvement of Photovoltaic Modules via Back Surface Cooling
Authors: Bevilacqua Piero , Perrella Stefania , Cirone Daniela , Bruno Roberto , Arcuri Natale
Published: February 2021

Crystalline silicon photovoltaics are a cardinal and well-consolidated technology for the achievement of energy efficiency goals, being installed worldwide for the production of clean electrical energy. However, their performance is strongly penalized by the thermal drift, mostly in periods of high solar radiation where solar cells reach considerably high temperatures. To limit this aspect, the employment of cooling systems appears a promising and viable solution. For this purpose, four different cooling systems, working on the photovoltaic (PV) panel back surface, were proposed and investigated in an experimental set-up located at the University of Calabria (Italy). Hourly electrical output power and efficiency were provided accounting for different meteorological conditions in several months of the experimental campaign. The results demonstrated that a simple spray cooling technique can provide an absolute increment of electrical efficiency of up to 1.6% and an average percentage increment of daily energy of up to 8% in hot months. More complex systems, based on ventilation or combining spray cooling and ventilation, were demonstrated not to be a viable option for PV performance improvement.
Prolongation of Battery Lifetime for Electric Buses through Flywheel Integration
Authors: Glücker Philipp , Kivekäs Klaus , Vepsäläinen Jari , Mouratidis Panagiotis , Schneider Maximilian , Rinderknecht Stephan , Tammi Kari
Published: February 2021

Electrification of transportation is an effective way to tackle climate change. Public transportation, such as electric buses, operate on predetermined routes and offer quiet operation, zero local emissions and high energy efficiency. However, the batteries of these buses are expensive and wear out in use. The battery ageing is expedited by fast charging and power spikes during operation. The contribution of this paper is the reduction of the power spikes and thus a prolonged battery lifetime. A novel hybrid energy storage system for electric buses is proposed by introducing a flywheel in addition to the existing battery. A simulation model of the hybrid energy storage system is presented, including a battery ageing model to measure the battery lifetime. The bus was simulated during its daily driving operation on different routes with different energy management strategies and flywheel configurations. These different flywheels as well as the driving cycle had a significant impact on the battery life increase. The proposed hybrid battery/flywheel storage system resulted in a battery lifetime increase of 20% on average.
Optimization of Thermal Parameters of the Coke Oven Battery by Modified Methodology of Temperature Measurement in Heating Flues as the Management Tool in the Cokemaking Industry
Authors: Kosyrczyk Ludwik , Stelmach Slawomir , Gaska Krzysztof , Generowicz Agnieszka , Iwaszczuk Natalia , Kardaś Dariusz
Published: February 2021

Coke production is still of great economic importance due to its crucial role in the steel production process. The reliability of the operation of coke oven batteries depends on the maintenance of good technical condition of their ceramic massif, which in turn requires ensuring proper operation of the heating system and maintaining temperature stability in the heating flues. Regularly performed temperature measurements in heating flues due to the size of the battery and the dynamics of accompanying processes do not reflect the actual thermal state of the object at a given time. Corrections commonly introduced to the results of temperature measurements in heating flues, taking into account so-called reversion, significantly improve the accuracy of the obtained measurement results. However, still the interpretation of the results of temperature measurements in the coke oven battery heating flues does not take into account its changes during the coking cycle, even though they reach up to 60 K. The article discusses the usability of the introduction of a new, additional correction to the temperature measured in the heating flues enabling a more precise assessment of the current thermal state of the coke oven battery. The use of the method will allow for reduction of the fuel gas consumption and limitation of emissions resulting from its combustion and can be used as an effective tool for decision making.
Analysis of Thermodynamic Cycles of Heat Pumps and Magnetic Refrigerators Using Mathematical Models
Authors: Baglivo Cristina , Congedo Paolo Maria , Donno Pasquale Antonio
Published: February 2021

This paper proposes a critical review of the different aspects concerning magnetic refrigeration systems, and performs a detailed analysis of thermodynamic cycles, using mathematical models found in the literature. Langevin’s statistical mechanical theory faithfully describes the physical operation of a refrigeration machine working according to a magnetic Ericsson cycle. Results of mathematical and real experimental models are compared to deduce which best describes the Ericsson cycle. The theoretical data are not perfectly consistent with the experimental data; there is a maximum deviation of about 30%. Numerical and experimental data confirm that very high Coefficient of Performance (COP) values of more than 20 can be achieved. The analysis of the Brayton cycle consisted of finding the mathematical model that considers the irreversibility of these machines. Starting from the thermodynamic properties of magnetocaloric materials based on statistical mechanics, the efficiency of an irreversible Brayton regenerative magnetic refrigeration cycle is studied. Considering the irreversibility in adiabatic transformations, the lower limit of the optimal ratio of two magnetic fields is determined, obtaining a valid optimization criterion for these machines operating according to a Brayton cycle. The results show that the Ericsson cycle achieves a higher Coefficient of Performance than the Brayton cycle, which has a higher cooling capacity as it operates with a larger temperature difference between the magnetocaloric material and source.
Power-to-X in Denmark: An Analysis of Strengths, Weaknesses, Opportunities and Threats
Authors: Skov Iva Ridjan , Schneider Noémi , Schweiger Gerald , Schöggl Josef-Peter , Posch Alfred
Published: February 2021

Power-to-X is an upcoming sector-coupling technology that can play a role in the decarbonisation of energy systems. The aim of this study was to widen the current knowledge of strengths, weaknesses, opportunities, and threats (SWOT) of this innovative technology in the Danish context by utilizing the analytic hierarchy process (AHP) to evaluate and compare perception of academic and industrial experts. The results of this analysis indicate that the external factors such as current policy framework are more important than the internal technology related factors. Further, positive factors predominate negative ones, with academic experts indicating strengths as the most important category and practitioners’ opportunities. All experts consider the country being a P2X knowledge hub as one of the most important factors, and in the given context of the Danish energy system, wind developments and Danish industrial environment, seizing this opportunity could be the biggest enabler for P2X success.