bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of Torque Ripple of a Spoke-Type Interior Permanent Magnet Machine
Authors: Chu Guoyu , Dutta Rukmi , Pouramin Alireza , Rahman Muhammed Fazlur
Published: June 2020

This paper investigates the theoretical reasons behind the low torque ripple of a fractional-slot concentrated-winding (FSCW) spoke-type interior permanent-magnet (IPM) machine obtained via a genetic algorithm-based optimization. To better understand the torque performance of the IPMM, this paper uses the frozen permeability method to segregate the overall torque into four components—magnet torque, reluctance torque, cogging torque, and the torque caused by cross-magnetization. Equations and detailed procedures of the torque separation method are discussed in the paper. Analysis of the separated torque components reveals that the counteraction between ripples of different torques leads to the low torque ripple. At high-load conditions, the magnetic saturation alters the torque ripples caused by cross-magnetization to offset ripples of other components resulting in minimization of the overall torque ripple. A detailed parametric analysis of the geometric parameters was carried out to understand their effect in producing minimum torque ripple in the optimized design. In the end, a prototype was built and used for the verification of the torque separation method and the analytical findings based on it.
Herbivore Gender Effects on Volatile Induction in Aspen and on Olfactory Responses in Leaf Beetles
Authors: Li Tao , Grauer-Gray Kristen , Holopainen Jarmo K. , Blande James D.
Published: June 2020

Hybrid aspen (Populus tremula × tremuloides Michx.) is a fast-growing tree species used for short-rotation forestry in northern latitudes. Aspen species have a rich herbivore fauna, including defoliating leaf beetles that induce emissions of volatile organic compounds (VOCs) when feeding on aspen leaves. We investigated the differential induction of VOCs by male and female Phratora laticollis leaf beetles feeding on hybrid aspen and the differences in the orientation of beetles in response to gender-specific induced VOCs. The hypotheses for the study were (1) the VOCs in the headspace of plants infested with beetles of the two genders individually and in mixed aggregates would vary subtly, and (2) foraging adult beetles would be able to detect differences in VOC blends and use them to fine-tune their orientation choices. In Y-tube bioassays, both females and males preferred VOCs from leaves damaged by one gender (females or males) over undamaged leaves. However, if leaves were damaged by a two-gender population, neither females nor males indicated a preference over volatiles of undamaged leaves. Leaves damaged by both beetle genders simultaneously had significantly increased green leaf volatile (GLV), benzenoid and homoterpene emissions compared to undamaged leaves. Emissions of these compounds possibly indicate higher herbivore pressure and a higher risk of attack by parasitoids and predators and could thus be the cause of the lack of beetle preference. Our findings provide new basic information on gender-based host plant selection by herbivores and may be helpful in the development of sustainable biogenic VOC-based herbivore-control methods for intensive short-rotation hybrid aspen production.
A Comparative Study of the Performance of Slender Reinforced Concrete Columns with Different Cross-Sectional Shapes
Authors: Abdualrahman Safaa Qays , Al-Zuhairi Alaa Hussein
Published: June 2020

Most reinforced concrete (RC) structures are constructed with square/rectangular columns. The cross-section size of these types of columns is much larger than the thickness of their partitions. Therefore, parts of these columns are protruded out of the partitions. The emergence of columns edges out of the walls has some disadvantages. This limitation is difficult to be overcome with square or rectangular columns. To solve this problem, new types of RC columns called specially shaped reinforced concrete (SSRC) columns have been used as hidden columns. Besides, the use of SSRC columns provides many structural and architectural advantages as compared with rectangular columns. Therefore, this study was conducted to explain the structural performance of slender SSRC columns experimentally and numerically via nonlinear finite element analysis. The study is based on nine RC specimens tested up to failure, as well as eighteen finite element (FE) models analyzed by Abaqus soft wear program. The use of SSRC columns led to increase strength by about 12% and reduce deformations, especially with slenderness ratio more than 40 as compared with equivalent square-shaped columns. Two design formulas were proposed to determine the compressive strength of SSRC columns under concentric loading. The results obtained indicate a good structural performance of SSRC columns when compared with equivalent square-shaped columns.
Spectroscopic and Molecular Modeling Investigation on the Interaction between Folic Acid and Bovine Lactoferrin from Encapsulation Perspectives
Authors: Aprodu Iuliana , Dumitrașcu Loredana , Râpeanu Gabriela , Bahrim Gabriela-Elena , Stănciuc Nicoleta
Published: June 2020

The impact of thermal treatment on the ability of lactoferrin (FL) to bind folic acid (FA) was investigated by employing fluorescence spectroscopy, molecular dynamics and docking tests. The structural and conformational particularities of LF upon heating at 80 °C and 100 °C were first estimated based on the intrinsic fluorescence changes in respect to the native protein. The emission spectra indicated gradual unfolding events accompanied by Trp exposure with increasing temperature. In agreement with the experimental results, molecular modeling investigations showed that the secondary and tertiary structure of LF are slightly affected by the thermal treatment. Some minor unfolding events related particularly to the α-helical regions of LF were observed when the temperature increased to 100 °C. The LF fluorescence quenching upon FA addition indicated that a static mechanism stands behind LF-FA complex formation. Regardless of the simulated temperature, the hydrogen bonds played an important role in regulating the interaction between the protein and ligand. FA binding to LF equilibrated at different temperatures occurred spontaneously, and all complexes displayed good thermodynamic stability. The obtained results support the suitability of LF as biocompatible material, for obtaining micro- and nanoparticles for delivery of dietary supplements or for enhancing the functionality of target delivery systems.
G9a Is SETting the Stage for Colorectal Oncogenesis
Authors: Bergin Christopher J. , Benoit Yannick D.
Published: June 2020

Recently, Kato et al. reported recurrent activating mutations in the SET domain of histone methyltransferase G9a, driving an oncogenic cascade in melanoma. The authors also reported correlations between G9a expression and the regulation of the canonical WNT pathway. Although we could not observe such mutations in human colorectal adenocarcinoma, newly reported findings are of high relevance to colorectal cancer, as WNT target gene signatures were closely associated with G9a expression. Here, we put into perspective such new results on G9a expression in colorectal cancers and the potential relationship with tumor heterogeneity and acquisition of neoplastic stemness.
Cytogenetic Characterization of Seven Novel satDNA Markers in Two Species of Spined Loaches (Cobitis) and Their Clonal Hybrids
Authors: Marta Anatolie , Dedukh Dmitry , Bartoš Oldřich , Majtánová Zuzana , Janko Karel
Published: June 2020

Interspecific hybridization is a powerful evolutionary force. However, the investigation of hybrids requires the application of methodologies that provide efficient and indubitable identification of both parental subgenomes in hybrid individuals. Repetitive DNA, and especially the satellite DNA sequences (satDNA), can rapidly diverge even between closely related species, hence providing a useful tool for cytogenetic investigations of hybrids. Recent progress in whole-genome sequencing (WGS) offers unprecedented possibilities for the development of new tools for species determination, including identification of species-specific satDNA markers. In this study, we focused on spined loaches (Cobitis, Teleostei), a group of fishes with frequent interspecific hybridization. Using the WGS of one species, C. elongatoides, we identified seven satDNA markers, which were mapped by fluorescence in situ hybridization on mitotic and lampbrush chromosomes of C. elongatoides, C. taenia and their triploid hybrids (C. elongatoides × 2C. taenia). Two of these markers were chromosome-specific in both species, one had centromeric localization in multiple chromosomes and four had variable patterns between tested species. Our study provided a novel set of cytogenetic markers for Cobitis species and demonstrated that NGS-based development of satDNA cytogenetic markers may provide a very efficient and easy tool for the investigation of hybrid genomes, cell ploidy, and karyotype evolution.
A Stop-Gain Mutation within MLPH Is Responsible for the Lilac Dilution Observed in Jacob Sheep
Authors: Posbergh Christian J. , Staiger Elizabeth A. , Huson Heather J.
Published: June 2020

A coat color dilution, called lilac, was observed within the Jacob sheep breed. This dilution results in sheep appearing gray, where black would normally occur. Pedigree analysis suggested an autosomal recessive inheritance. Whole-genome sequencing of a dilute case, a known carrier, and sixteen non-dilute sheep was used to identify the molecular variant responsible for the coat color change. Through investigation of the genes MLPH, MYO5A, and RAB27A, we discovered a nonsynonymous mutation within MLPH, which appeared to match the reported autosomal recessive nature of the lilac dilution. This mutation (NC_019458.2:g.3451931C>A) results in a premature stop codon being introduced early in the protein (NP_001139743.1:p.Glu14*), likely losing its function. Validation testing of additional lilac Jacob sheep and known carriers, unrelated to the original case, showed a complete concordance between the mutation and the dilution. This stop-gain mutation is likely the causative mutation for dilution within Jacob sheep.
Geo-Epidemiology of Malaria at the Health Area Level, Dire Health District, Mali, 2013–2017
Authors: Cissoko Mady , Sagara Issaka , Sankaré Moussa H. , Dieng Sokhna , Guindo Abdoulaye , Doumbia Zoumana , Allasseini Balam , Traore Diahara , Fomba Seydou , Bendiane Marc Karim , Landier Jordi , Dessay Nadine , Gaudart Jean
Published: June 2020

Background: According to the World Health Organization, there were more than 228 million cases of malaria globally in 2018, with 93% of cases occurring in Africa; in Mali, a 13% increase in the number of cases was observed between 2015 and 2018; this study aimed to evaluate the impact of meteorological and environmental factors on the geo-epidemiology of malaria in the health district of Dire, Mali. Methods: Meteorological and environmental variables were synthesized using principal component analysis and multiple correspondence analysis, the relationship between malaria incidence and synthetic indicators was determined using a multivariate general additive model; hotspots were detected by SaTScan. Results: Malaria incidence showed high inter and intra-annual variability; the period of high transmission lasted from September to February; health areas characterized by proximity to the river, propensity for flooding and high agricultural yield were the most at risk, with an incidence rate ratio of 2.21 with confidence intervals (95% CI: 1.85–2.58); malaria incidence in Dire declined from 120 to 20 cases per 10,000 person-weeks between 2013 and 2017. Conclusion: The identification of areas and periods of high transmission can help improve malaria control strategies.
Changes in Overall Participation Profile of Youth with Physical Disabilities Following the PREP Intervention
Authors: Hoehne Colin , Baranski Brittany , Benmohammed Louiza , Bienstock Liam , Menezes Nathan , Margolese Noah , Anaby Dana
Published: June 2020

The Pathways and Resources for Engagement and Participation (PREP), an environmental-based intervention, is effective in improving the participation of youth with disabilities in specific targeted activities; however, its potential impact on overall participation beyond these activities is unknown. This study examined the differences in participation levels and environmental barriers and supports following the 12-week PREP intervention. Existing data on participation patterns and environmental barriers and supports, measured by the Participation and Environment Measure for Children and Youth, pre-and post-PREP intervention, were statistically analyzed across 20 youth aged 12 to 18 (mean = 14.4, standard deviation (SD) = 1.82) with physical disabilities in three settings: home, school and community. Effect sizes were calculated using Cohen’s d. Following PREP, youth participated significantly less often at home (d = 2.21; 95% Confidence Interval (CI) [1.79, 2.96]), more often (d = 0.57; 95% CI [−0.79, −0.14]) and in more diverse activities (d = 0.51; 95% CI [−1.99, −0.51]) in the community. At school, significantly greater participation was observed in special school roles (t = −2.46. p = 0.024). Involvement and desire for change remained relatively stable across all settings. A substantial increase in community environmental supports was observed (d = 0.67), with significantly more parents reporting availability of, and access to information as a support (χ2 = 4.28, p = 0.038). Findings lend further support to the effectiveness of environmental-based interventions, involving real-life experiences.
Self-Medication and Safety Profile of Medicines Used among Pregnant Women in a Tertiary Teaching Hospital in Jimma, Ethiopia: A Cross-Sectional Study
Authors: Ahmed Seid Mussa , Sundby Johanne , Aragaw Yesuf Ahmed , Abebe Fekadu
Published: June 2020

Background: Despite the potential foetal and maternal risks of self-medication, studies on self-medication and safety profile of medicines used during pregnancy are scarce. This study determined the prevalence, predictors and safety profile of medicines used for self-medication during pregnancy at Jimma University Medical Centre (JUMC) in Ethiopia. Methods: A hospital-based cross sectional study was conducted on 1117 hospitalized pregnant women or postpartum women in the maternity and gynaecology wards at JUMC between February and June 2017. Data were collected using an interviewer-administered structured questionnaire and by reviewing patient medical records. Data were analysed using descriptive statistics and logistic regression. Result: Nearly 3 out of 10 women reported taking at least one type of conventional medicine for self-medication, mainly analgesics 92.3%. Almost 75.0% of the self-medicated women used medicines classified as probably safe and 13.6% as potentially risky to use during pregnancy. Medicinal plant use, religion and access to a health facility near their residency were significantly associated with self-medication during pregnancy. Conclusions: Self-medication is common among pregnant women at JUMC. Most women used medicines classified as safe to use during pregnancy. There is need for enlightenment of pregnant women on the potential dangers of self-medication during pregnancy to prevent foetal and maternal risks.
COVID-19: Time for Post-Exposure Prophylaxis?
Authors: Gentile Ivan , Maraolo Alberto , Piscitelli Prisco , Colao Annamaria
Published: June 2020

From a healthcare perspective, infection due to the novel coronavirus SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) and the ensuing syndrome called COVID-19 (coronavirus disease 2019) represents the biggest challenge the world has faced in several decades. Particularly worrisome are the high contagiousness of the virus and the saturation of hospitals’ capacity due to overwhelming caseloads. Non-pharmaceutical interventions such as quarantine and inter-personal distancing are crucial to limiting the spread of the virus in the general population, but more tailored interventions may be needed at an individual level on a case-by-case basis. In this perspective, the most insidious situation is when an individual has contact with a contagious subject without adequate protection. If rapidly recognized afterwards, this occurrence may be promptly addressed through a post-exposure chemoprophylaxis (PEP) with antiviral drugs. This strategy has been implemented for other respiratory viruses (influenza above all) and was successfully used in South Korea among healthcare workers against the Middle East respiratory syndrome (MERS) coronavirus, by providing people who were exposed to high-risk contacts with lopinavir-ritonavir plus ribavirin. Initial experiences with the use of hydroxychloroquine to prevent COVID-19 also seem promising. Post-exposure chemoprophylaxis might help mitigate the spread of SARS-CoV-2 in the current phase of the COVID-19 pandemic.
Development of the Hearing Rehabilitation for Older Adults (HeRO) Healthcare Mobile Application and Its Likely Utility for Elderly Users
Authors: Kwak Chanbeom , Kim Saea , You Sunghwa , Han Woojae
Published: June 2020

The present study aimed to develop a healthcare application for the elderly who suspect or know they have a hearing loss, namely, the Hearing Rehabilitation for Older Adults (HeRO), which is available in a mobile device, and then to confirm its probability of acceptance among elderly users. Under a web server system, HeRO which had four types of tailored training for the aged auditory system (i.e., syllable, sentence, discourse, working memory) and a self-reported questionnaire to screen amount of the hearing loss was completed for the elderly. To verify whether the HeRO contents and functions were user-friendly to the elderly users, the technology acceptance model (TAM) was used. Forty-four older adults were asked to use the developed application for 10 days and then respond to a TAM questionnaire with 25 items. The Cronbach’s α coefficient of each subcategory was very high. The construct validity of all subcategories showed high eigenvalues using principal component analysis. Furthermore, our regression model statistically supported a persuasive intention to use the healthcare application because the elderly readily accept it and find it easy to manipulate. We expect the current technology to be applied to the general public as well as the elderly who want to explore digital health.
Seasonal Impacts of Particulate Matter Levels on Bike Sharing in Seoul, South Korea
Authors: Kim Hyungkyoo
Published: June 2020

Bike sharing is increasingly attracting more riders in cities around the world for its benefits regarding the urban environment and public health. The public bike sharing program of Seoul, South Korea, first launched in October 2015, is now widely spread around the city and serves more than 27,000 riders daily. However, concerns are being raised as rising air pollution levels in Seoul, represented by particulate matter (PM) levels, in recent years may negatively discourage citizens from using bike sharing. This study investigates the impact of PM10 and PM2.5 levels on bike sharing use in Seoul and seeks to identify any seasonal differences. A series of negative binomial regression models, which take into account control variables like weather conditions and calendar events, are adopted to empirically measure the impacts. Results show that the PM levels yield statistically significant negative impacts (p < 0.01) on bike sharing use throughout the year. The impacts are particularly stronger in winter and spring, when the PM levels are higher. Findings suggest that PM levels may operate as driving factors for bike sharing use in addition to meteorological conditions like temperature, humidity, and precipitation.
Unraveling Latent Aspects of Urban Expansion: Desertification Risk Reveals More
Authors: Egidi Gianluca , Zambon Ilaria , Tombolin Ilaria , Salvati Luca , Cividino Sirio , Seifollahi-Aghmiuni Samaneh , Kalantari Zahra
Published: June 2020

Urban expansion results in socioeconomic transformations with relevant impacts for peri-urban soils, leading to environmental concerns about land degradation and increased desertification risk in ecologically fragile districts. Spatial planning can help achieve sustainable land-use patterns and identify alternative locations for settlements and infrastructure. However, it is sometimes unable to comprehend and manage complex processes in metropolitan developments, fueling unregulated and mainly dispersed urban expansion on land with less stringent building constraints. Using the Mediterranean cities of Barcelona and Rome as examples of intense urbanization and ecological fragility, the present study investigated whether land use planning in these cities is (directly or indirectly) oriented towards conservation of soil quality and mitigation of desertification risk. Empirical results obtained using composite, geo-referenced indices of soil quality (SQI) and sensitivity to land desertification (SDI), integrated with high-resolution land zoning maps, indicated that land devoted to natural and semi-natural uses has lower soil quality in both contexts. The highest values of SDI, indicating high sensitivity to desertification, were observed in fringe areas with medium-high population density and settlement expansion. These findings reveal processes of land take involving buildable soils, sometimes of high quality, and surrounding landscapes in both cities. Overall, the results in this study can help inform land use planers and policymakers for conservation of high-quality soils, especially under weak (or partial) regulatory constraints.
A Multifactorial Evaluation of the Effects of Air Pollution and Meteorological Factors on Asthma Exacerbation
Authors: Yu Hong-Ren , Lin Chun-Hung Richard , Tsai Jui-Hsiu , Hsieh Yun-Ting , Tsai Ti-An , Tsai Chang-Ku , Lee Yi-Chen , Liu Ta-Yu , Tsai Chih-Min , Chen Chih-Cheng , Chang Chih-Hao , Hsu Te-Yao , Niu Chen-Kuang
Published: June 2020

In the real world, dynamic changes in air pollutants and meteorological factors coexist simultaneously. Studies identifying the effects of individual pollutants on acute exacerbation (AE) of asthma may overlook the health effects of the overall combination. A comprehensive study examining the influence of air pollution and meteorological factors is required. Asthma AE data from emergency room visits were collected from the Taiwan National Health Insurance Research Database. Complete monitoring data for air pollutants (SO2; NO2; O3; CO; PM2.5; PM10) and meteorological factors were collected from the Environmental Protection Agency monitoring stations. A bi-directional case-crossover analysis was used to investigate the effects of air pollution and meteorological factors on asthma AE. Among age group divisions, a 1 °C temperature increase was a protective factor for asthma ER visits with OR = 0.981 (95% CI, 0.971–0.991) and 0.985 (95% CI, 0.975–0.994) for pediatric and adult patients, respectively. Children, especially younger females, are more susceptible to asthma AE due to the effects of outdoor air pollution than adults. Meteorological factors are important modulators for asthma AE in both asthmatic children and adults. When studying the effects of air pollution on asthma AE, meteorological factors should be considered.
The Effect of TBB, as an Initiator, on the Biological Compatibility of PMMA/MMA Bone Cement
Authors: Hamajima Kosuke , Ozawa Ryotaro , Saruta Juri , Saita Makiko , Kitajima Hiroaki , Taleghani Samira Rahim , Usami Dan , Goharian Donya , Uno Mitsunori , Miyazawa Ken , Goto Shigemi , Tsukinoki Keiichi , Ogawa Takahiro
Published: June 2020

Acrylic bone cement is widely used in orthopedic surgery for treating various conditions of the bone and joints. Bone cement consists of methyl methacrylate (MMA), polymethyl methacrylate (PMMA), and benzoyl peroxide (BPO), functioning as a liquid monomer, solid phase, and polymerization initiator, respectively. However, cell and tissue toxicity caused by bone cement has been a concern. This study aimed to determine the effect of tri-n-butyl borane (TBB) as an initiator on the biocompatibility of bone cement. Rat spine bone marrow-derived osteoblasts were cultured on two commercially available PMMA-BPO bone cements and a PMMA-TBB experimental material. After a 24-h incubation, more cells survived on PMMA-TBB than on PMMA-BPO. Cytomorphometry showed that the area of cell spread was greater on PMMA-TBB than on PMMA-BPO. Analysis of alkaline phosphatase activity, gene expression, and matrix mineralization showed that the osteoblastic differentiation was substantially advanced on the PMMA-TBB. Electron spin resonance (ESR) spectroscopy revealed that polymerization radical production within the PMMA-TBB was 1/15–1/20 of that within the PMMA-BPO. Thus, the use of TBB as an initiator, improved the biocompatibility and physicochemical properties of the PMMA-based material.
Recent Advances in Electrospun Sustainable Composites for Biomedical, Environmental, Energy, and Packaging Applications
Authors: Liu Hao , Gough Christopher R. , Deng Qianqian , Gu Zhenggui , Wang Fang , Hu Xiao
Published: June 2020

Electrospinning has gained constant enthusiasm and wide interest as a novel sustainable material processing technique due to its ease of operation and wide adaptability for fabricating eco-friendly fibers on a nanoscale. In addition, the device working parameters, spinning solution properties, and the environmental factors can have a significant effect on the fibers’ morphology during electrospinning. This review summarizes the newly developed principles and influence factors for electrospinning technology in the past five years, including these factors’ interactions with the electrospinning mechanism as well as its most recent applications of electrospun natural or sustainable composite materials in biology, environmental protection, energy, and food packaging materials.
Novel Comprehensive Bioinformatics Approaches to Determine the Molecular Genetic Susceptibility Profile of Moderate and Severe Asthma
Authors: Zayed Hatem
Published: June 2020

Background: Asthma is a chronic inflammatory condition linked to hyperresponsiveness in the airways. There is currently no cure available for asthma, and therapy choices are limited. Asthma is the result of the interplay between genes and the environment. The exact molecular genetic mechanism of asthma remains elusive. Aims: The aim of this study is to provide a comprehensive, detailed molecular etiology profile for the molecular factors that regulate the severity of asthma and pathogenicity using integrative bioinformatics tools. Methods: The GSE43696 omnibus gene expression dataset, which contains 50 moderate cases, 38 severe cases, and 20 healthy controls, was used to investigate differentially expressed genes (DEGs), susceptible chromosomal loci, gene networks, pathways, gene ontologies, and protein–protein interactions (PPIs) using an intensive bioinformatics pipeline. Results: The PPI network analysis yielded DEGs that contribute to interactions that differ from moderate-to-severe asthma. The combined interaction scores resulted in higher interactions for the genes STAT3, AGO2, COL1A1, CLCN6, and KSR for moderate asthma and JAK2, INSR, ERBB2, NR3C1, and PTK6 for severe asthma. Enrichment analysis (EA) demonstrated differential enrichment between moderate and severe asthma phenotypes; the ion transport regulation pathway was significantly enhanced in severe asthma phenotypes compared to that in moderate asthma phenotypes and involved PER2, GCR, IRS-2, KCNK7, KCNK6, NOX1, and SCN7A. The most enriched common pathway in both moderate and severe asthma is the development of the glucocorticoid receptor (GR) signaling pathway followed by glucocorticoid-mediated inhibition of proinflammatory and proconstrictory signaling in the airway of smooth muscle cell pathways. Gene sets were shared between severe and moderate asthma at 16 chromosome locations, including 17p13.1, 16p11.2, 17q21.31, 1p36, and 19q13.2, while 60 and 48 chromosomal locations were unique for both moderate and severe asthma, respectively. Phylogenetic analysis for DEGs showed that several genes have been intersected in phases of asthma in the same cluster of genes. This could indicate that several asthma-associated genes have a common ancestor and could be linked to the same biological function or gene family, implying the importance of these genes in the pathogenesis of asthma. Conclusion: New genetic risk factors for the development of moderate-to-severe asthma were identified in this study, and these could provide a better understanding of the molecular pathology of asthma and might provide a platform for the treatment of asthma.
OsCpn60β1 is Essential for Chloroplast Development in Rice (Oryza sativa L.)
Authors: Wu Qingfei , Zhang Cheng , Chen Yue , Zhou Kaiyue , Zhan Yihua , Jiang Dean
Published: June 2020

The chaperonin 60 (Cpn60) protein is of great importance to plants due to its involvement in modulating the folding of numerous chloroplast protein polypeptides. In chloroplasts, Cpn60 is differentiated into two subunit types—Cpn60α and Cpn60β and the rice genome encodes three α and three β plastid chaperonin subunits. However, the functions of Cpn60 family members in rice were poorly understood. In order to investigate the molecular mechanism of OsCpn60β1, we attempted to disrupt the OsCpn60β1 gene by CRISPR/Cas9-mediated targeted mutagenesis in this study. We succeeded in the production of homozygous OsCpn60β1 knockout rice plants. The OsCpn60β1 mutant displayed a striking albino leaf phenotype and was seedling lethal. Electron microscopy observation demonstrated that chloroplasts were severely disrupted in the OsCpn60β1 mutant. In addition, OsCpn60β1 was located in the chloroplast and OsCpn60β1 is constitutively expressed in various tissues particularly in the green tissues. The label-free qualitative proteomics showed that photosynthesis-related pathways and ribosomal pathways were significantly inhibited in OsCpn60β1 mutants. These results indicate that OsCpn60β1 is essential for chloroplast development in rice.
In-Silico Characterization of Glycosyl Hydrolase Family 1 β-Glucosidase from Trichoderma asperellum UPM1
Authors: Mohamad Sobri Mohamad Farhan , Abd-Aziz Suraini , Abu Bakar Farah Diba , Ramli Norhayati
Published: June 2020

β-glucosidases (Bgl) are widely utilized for releasing non-reducing terminal glucosyl residues. Nevertheless, feedback inhibition by glucose end product has limited its application. A noticeable exception has been found for β-glucosidases of the glycoside hydrolase (GH) family 1, which exhibit tolerance and even stimulation by glucose. In this study, using local isolate Trichoderma asperellum UPM1, the gene encoding β-glucosidase from GH family 1, hereafter designated as TaBgl2, was isolated and characterized via in-silico analyses. A comparison of enzyme activity was subsequently made by heterologous expression in Escherichia coli BL21(DE3). The presence of N-terminal signature, cis-peptide bonds, conserved active site motifs, non-proline cis peptide bonds, substrate binding, and a lone conserved stabilizing tryptophan (W) residue confirms the identity of Trichoderma sp. GH family 1 β-glucosidase isolated. Glucose tolerance was suggested by the presence of 14 of 22 known consensus residues, along with corresponding residues L167 and P172, crucial in the retention of the active site’s narrow cavity. Retention of 40% of relative hydrolytic activity on ρ-nitrophenyl-β-D-glucopyranoside (ρNPG) in a concentration of 0.2 M glucose was comparable to that of GH family 1 β-glucosidase (Cel1A) from Trichoderma reesei. This research thus underlines the potential in the prediction of enzymatic function, and of industrial importance, glucose tolerance of family 1 β-glucosidases following relevant in-silico analyses.
Origins of Hyperbolicity in Color Perception
Authors: Prencipe Nicoletta , Garcin Valérie , Provenzi Edoardo
Published: June 2020

In 1962, H. Yilmaz published a very original paper in which he showed the striking analogy between Lorentz transformations and the effect of illuminant changes on color perception. As a consequence, he argued that a perceived color space endowed with the Minkowski metric is a good approximation to model color vision. The contribution of this paper is twofold: firstly, we provide a mathematical formalization of Yilmaz’s argument about the relationship between Lorentz transformations and the perceptual effect of illuminant changes. Secondly, we show that, within Yilmaz’s model, the color space can be coherently endowed with the Minkowski metric only by imposing the Euclidean metric on the hue-chroma plane. This fact motivates the need of further investigation about both the proper definition and interrelationship among the color coordinates and also the geometry and metrics of perceptual color spaces.
Experimental Investigation on Vortex-Induced Vibration of a Flexible Pipe under Higher Mode in an Oscillatory Flow
Authors: Ren Haojie , Zhang Mengmeng , Cheng Jingyun , Cao Peimin , Xu Yuwang , Fu Shixiao , Liu Chang
Published: June 2020

Different from the previous studies of the vortex-induced vibration (VIV) dominated by first mode of flexible pipe in an oscillatory flow, the features of a higher mode dominated are experimentally investigated in the ocean basin. The flexible pipe is forced to harmonically oscillate with different combinations of a period and amplitude. The design dominant mode consists of first and second modes under the maximum reduced velocity (VR) of approximately 5.5 with a KC number ranging from 22 to 165. The VIV responses between only the excited first mode and the excited higher mode are compared and studied using displacement reconstruction and wavelet transform methods. The discrepancies of spatial and temporal response between smaller and larger KC numbers (KC = 56 and 121) are first observed. The strong alternate mode dominance and lock-in phenomena occur in the case of larger KC numbers, while they cannot be observed in the case of smaller KC numbers under higher modes. The VIV dominant frequency in the in-line (IL) direction is found to be always triple the oscillatory flow frequency and not twice that in the cross flow (CF) direction. The dominant frequency in the CF direction can be predicted by the Strouhal law, and the Strouhal number is approximately 0.18 under VR = 5.5, which is not affected by the excited mode. Moreover, differences of response motion trajectory are also revealed in this paper. The present work improves the basic understanding of vessel motion induced VIV and provides helpful references for developing prediction methods of VIV in an oscillatory flow.
Flexural Behavior of Fire-Damaged Prefabricated RC Hollow Slabs Strengthened with CFRP versus TRM
Authors: Sui Zheng-Ang , Dong Kun , Jiang Jitong , Yang Shutong , Hu Kexu
Published: June 2020

In this paper, carbon fiber reinforced polymer (CFRP) and textile reinforced mortar (TRM) strengthening techniques were proposed to retrofit and strengthen fire-damaged prefabricated concrete hollow slabs. A total of six slabs, from an actual multi-story masonry building, were tested to investigate the flexural performance of reinforced concrete (RC) hollow slabs strengthened with TRM and CFRP. The investigated parameters included the strengthening method (CFRP versus TRM), the number of CFRP layers, and with or without fire exposure. One unstrengthened slab and one TRM strengthened slab served as the control specimens without fire exposure. The remaining four slabs were first exposed to ISO-834 standard fire for 1 h, and then three of them were strengthened with CFRP or TRM. Through the four-point bending tests at ambient temperature, the failure modes, load and deformation response were recorded and discussed. Both CFRP and TRM strengthening methods can significantly increase the cracking load and peak load of the fire-damaged hollow slabs, as well as the stiffness in the early stage. The prefabricated hollow slabs strengthened by CFRP have better performance in the ultimate bearing capacity, but the ductility reduced with the increase of CFRP layers. Meanwhile, the TRM strengthening technique is a suitable method for the performance improvement of fire-damaged hollow slabs, in terms of not only the load capacity, especially the cracking load, but also the flexural stiffness and deformation capacity.
Dynamic Ferromagnetic Hysteresis Modelling Using a Preisach-Recurrent Neural Network Model
Authors: Grech Christian , Buzio Marco , Pentella Mariano , Sammut Nicholas
Published: June 2020

In this work, a Preisach-recurrent neural network model is proposed to predict the dynamic hysteresis in ARMCO pure iron, an important soft magnetic material in particle accelerator magnets. A recurrent neural network coupled with Preisach play operators is proposed, along with a novel validation method for the identification of the model’s parameters. The proposed model is found to predict the magnetic flux density of ARMCO pure iron with a Normalised Root Mean Square Error (NRMSE) better than 0.7%, when trained with just six different hysteresis loops. The model is evaluated using ramp-rates not used in the training procedure, which shows the ability of the model to predict data which has not been measured. The results demonstrate that the Preisach model based on a recurrent neural network can accurately describe ferromagnetic dynamic hysteresis when trained with a limited amount of data, showing the model’s potential in the field of materials science.
Experimental Investigation of Material Properties and Self-Healing Ability in a Blended Cement Mortar with Blast Furnace Slag
Authors: Na Seunghyun , Zhang Wenyan , Taniguchi Madoka , Quy Nguyen Xuan , Hama Yukio
Published: June 2020

This paper presents the results of an experimental investigation on the material properties and self-healing ability of a blended cement mortar incorporating blast furnace slag (BFS). The effect of different types and Blaine fineness of BFS on the material properties and self-healing was investigated. Thirteen cement mixtures with BFS of different types and degrees of Blaine fineness are tested to evaluate the mechanical properties, namely compressive strength, bending strength, freeze–thaw, and accelerated carbonation. The pore structure is examined by means of mercury intrusion porosimetry. Seven blended mortar mixtures incorporating BFS for cement are used to evaluate the mechanical properties after applying freeze–thaw cycles until the relative dynamic modulus of elasticity reached 60%. The experimental results reveal that incorporating BFS improves the mechanical properties and self-healing ability. In the investigation of self-healing, smaller particle and high replacement ratios of BFS contribute to increasing the relative dynamic modulus of elasticity and decreasing the carbonation coefficient in the mortar after re-water curing. Moreover, BFS’s larger particles and high replacement ratio are found to provide better self-healing ability. A regression equation is created to predict the relative dynamic modulus of elasticity in mortar considering the Blaine fineness, BFS replacement ratio, and curing conditions.
Photoelectrochromic Devices with Enhanced Power Conversion Efficiency
Authors: Dokouzis Alexandros , Zoi Dimitra , Leftheriotis George
Published: June 2020

In the present work, we propose a new architecture for partly covered photoelectrochromic devices with a modified anode layout, so that the TiO2 film is deposited first on the substrate, covering a small part of its surface, followed by the WO3 film that covers the remaining device area. As a result, the TiO2 film can be subjected to the proper thermal and chemical treatment without affecting the electrochromic performance of the WO3 film. The proposed design led to photoelectrochromic (PEC) devices with a power conversion efficiency (PCE) four times higher than that of typical partly covered devices, with a measured maximum of 4.9%. This, in turn, enabled a reduction in the total area covered by the photovoltaic unit of the devices by four times (to 5% from 20%), thus reducing its visual obstruction, without affecting the depth, uniformity and speed of coloration. A detailed study of the parameters affecting the performance of the new devices revealed that, with the cover ratio decreasing, PCE was increasing. The photocoloration efficiency also exhibited the same trend for cover ratio values below 15%. Storage of the devices in short circuit conditions was found to accelerate optical reversibility without affecting their photovoltaic and optical performance.
Fracture Toughness of Hollow Glass Microsphere-Filled Iron Matrix Syntactic Foams
Authors: Lehmhus Dirk , Weise Jörg , Szlancsik Attila , Orbulov Imre Norbert
Published: June 2020

In this study, iron-based metal matrix syntactic foam (MMSF) containing hollow glass microspheres as filler was investigated with respect to notch sensitivity aspects. The MMSF was produced by means of metal powder injection molding. The notch sensitivity was studied via (i) elastic-plastic fracture mechanics measurements (determination of R-curves based on three-point bending tests) and (ii) Charpy impact tests. In both cases, the samples were machined with two different (U- and V-shaped) notch geometries. The critical J-integral value was determined for both notch types, which resulted in lower fracture toughness values in the case of the V-shaped notches and thus notch sensitivity of the material. This finding can be connected to the characteristics of the deformation zone and the associated stress concentration at the tip of the machined notches. The results were confirmed by Charpy impact tests showing ~30% higher impact energy in the case of the U-shaped notch. The failure modes were investigated by means of scanning electron microscopy. In contrast to the bulk material, the MMSF showed brittle fracture behavior.
Machine Learning Modeling of Aerobic Biodegradation for Azo Dyes and Hexavalent Chromium
Authors: Ahmad Zulfiqar , Zhong Hua , Mosavi Amir , Sadiq Mehreen , Saleem Hira , Khalid Azeem , Mahmood Shahid , Nabipour Narjes
Published: June 2020

The present study emphasizes the efficacy of a biosurfactant-producing bacterial strain Klebsiella sp. KOD36 in biodegradation of azo dyes and hexavalent chromium individually and in a simultaneous system. The bacterial strain has exhibited a considerable potential for biodegradation of chromium and azo dyes in single and combination systems (maximum 97%, 94% in an individual and combined system, respectively). Simultaneous aerobic biodegradation of azo dyes and hexavalent chromium (SBAHC) was modeled using machine learning programming, which includes gene expression programming, random forest, support vector regression, and support vector regression-fruit fly optimization algorithm. The correlation coefficient includes the dispersion index, and the Willmott agreement index was employed as statistical metrics to assess the performance of each model separately. In addition, the Taylor diagram was used to further investigate the methods used. The findings of the present study were that the support vector regression-fruitfly optimization algorithm (SVR-FOA) with correlation coefficient (CC) of 0.644, (scattered index) SI of 0.374, and (Willmott’s index of agreement) WI of 0.607 performed better than the autonomous support vector regression (SVR), gene expression programming (GEP), and random forest (RF) methods. In addition, the standalone SVR model with CC of 0.146, SI of 0.473, and WI of 0.408 ranked the second best. In summary, the SBAHC can be accurately estimated using the hybrid SVR-FOA method. In other words, FOA has proven to be a powerful optimization algorithm for increasing the accuracy of the SVR method.
Modelling the Process to Access the Spanish Public University System Based on Structural Equation Models
Authors: Hervás Antonio , Soriano Pedro Pablo , Olmos Joan Guàrdia i , Peró Maribel , Capilla Roberto , Montañana José Miguel
Published: June 2020

Currently, one of the challenges of universities is attracting talent in students, researchers, and teachers. The transition from high school to college requires a student to take a succession of decisions that will shape their future. For this reason, knowledge of the motivations of the students, their family, and their personal environment, to choose a particular degree and/or university to pursue their higher studies, would allow universities to efficiently adjust their recruitment strategies. In this article, a study was developed based on a structural equation model of the access to the Spanish Public University System (SUPE), which can help with supply and demand problems, recruitment actions and policies, and other strategic decisions. This was done through an extensive survey of first-year students of Spanish universities. The results allowed us to obtain the parameters of the model, which showed that the fit between the model and the data obtained were excellent at a global level and acceptable as well in all knowledge areas. The objective of the structural model was to provide a general view of the behavior of the students when deciding the degree and university in which they are going to study, and can help in the decision making of university leaders and to understand some behaviors of the Spanish Public University System.
The Pta-AckA Pathway Regulates LrgAB-Mediated Pyruvate Uptake in Streptococcus mutans
Authors: Ahn Sang-Joon , Desai Shailja , Lin Min , Rice Kelly C.
Published: June 2020

Pyruvate forms the central node of carbon metabolism and promotes growth as an alternative carbon source during starvation. We recently revealed that LrgAB functions as a stationary phase pyruvate uptake system in Streptococcus mutans, the primary causative agent of human dental caries, but its underlying regulatory mechanisms are still not clearly understood. This study was aimed at further characterizing the regulation of LrgAB from a metabolomic perspective. We utilized a series of GFP quantification, growth kinetics, and biochemical assays. We disclosed that LrgAB is critical for pyruvate uptake especially during growth under low-glucose stress. Inactivation of the Pta-Ack pathway, responsible for the conversion of acetyl-CoA to acetate, completely inhibits stationary phase lrgAB induction and pyruvate uptake, and renders cells insensitive to external pyruvate as a signal. Inactivation of Pfl, responsible for the conversion of pyruvate to acetyl-CoA under anaerobic conditions, also affected stationary phase pyruvate uptake. This study explores the metabolic components of pyruvate uptake regulation through LrgAB, and highlights its potential as a metabolic stimulator, contributing to the resuscitation and survival of S. mutans cells during nutritional stress.
Antimicrobial Activity of Six International Artisanal Kefirs against Bacillus cereus, Listeria monocytogenes, Salmonella enterica Serovar Enteritidis, and Staphylococcus aureus
Authors: Sindi Abrar , Badsha Md. Bahadur , Nielsen Barbara , Ünlü Gülhan
Published: June 2020

Kefir, a fermented dairy beverage, exhibits antimicrobial activity due to many metabolic products, including bacteriocins, generated by lactic acid bacteria. In this study, the antimicrobial activities of artisanal kefir products from Fusion Tea (A), Britain (B), Ireland (I), Lithuania (L), the Caucuses region (C), and South Korea (K) were investigated against select foodborne pathogens. Listeria monocytogenes CWD 1198, Salmonella enterica serovar Enteritidis ATCC 13076, Staphylococcus aureus ATCC 25923, and Bacillus cereus ATCC 14579 were inhibited by artisanal kefirs made with kefir grains from diverse origins. Kefirs A, B, and I inhibited all bacterial indicator strains examined at varying levels, except Escherichia coli ATCC 12435 (non-pathogenic, negative control). Kefirs K, L, and C inhibited all indicator strains, except S. aureus ATCC 25923 and E. coli ATCC 12435. Bacteriocins present in artisanal kefirs were determined to be the main antimicrobials in all kefirs examined. Kefir-based antimicrobials are being proposed as promising natural biopreservatives as per the results of the study.