Character graphs with diameter three Ebrahimi, Mahdi
Proceedings of the American Mathematical Society,
November 1, 2020, 2020-11-00, Volume:
148, Issue:
11
Journal Article
Peer reviewed
Open access
For a finite group G, let \Delta (G) denote the character graph built on the set of degrees of the irreducible complex characters of G. In this paper, we show that if the diameter of \Delta (G) is ...equal to three, then the complement of \Delta (G) is bipartite. Also in this case, we determine the structure of the character graph \Delta (G).
In this paper, a novel frequency pattern and competent criterion are introduced for short-circuit-fault recognition in permanent-magnet synchronous motors (PMSMs). The frequency pattern is extracted ...from the monitored stator current analytically and the amplitude of sideband components at these frequencies is introduced as a proper criterion to determine the number of short-circuited turns. Impacts of the load variation on the proposed criterion are investigated in the faulty PMSM. In order to demonstrate the aptitude of the proposed criterion for precise short-circuit fault detection, the relation between the nominated criterion and the number of short-circuited turns is specified by the mutual information index. Therefore, a white Gaussian noise is added to the simulated stator current and robustness of the criterion is analyzed with respect to the noise variance. The occurrence and the number of short-circuited turns are predicted using support-vector machine as a classifier. The classification results indicate that the introduced criterion can detect the short-circuit fault incisively. Simulation results are verified by the experimental results.
Environmental and financial concerns have motivated road authorities to limit the utilization of natural resources in road construction, particularly the resources that cannot be renewed. To fulfill ...such requirements, pavement researchers have successfully utilized reclaimed asphalt pavement (RAP) materials as an attractive alternative to their natural counterparts. In practice, rejuvenators are often used to amend the properties of the RAP binder. The addition of the rejuvenator in the mixtures containing RAP materials could completely change the behavior of the mixtures. Such changes in the mechanical responses of the asphalt mixtures are essential aspects of pavements’ lifetime performance and should be considered during the asphalt mix design. Although the self-healing performance of asphalt mixtures prepared by virgin materials is well researched, a few research studies have been carried out to investigate the healing properties of asphalt mixtures prepared by RAP materials. This paper examines the influence of the addition of rice bran oil (RBO) capsules on the self-healing performance and mechanical properties of the asphalt mixtures containing various amounts of RAP: 20% and 40% and control mix containing no RAP material. In general, it was found that the addition of the capsules into the mixtures with RAP materials decreased the resilient modulus and flow number (FN) values. As a consequence of the fact that some part of the rejuvenator inside capsules is released into the mixture during mixing and compaction; moreover, the skeleton structure of capsules is weaker than aggregates, which allows the reduction in the maximum density. Further, the addition of capsules into the asphalt mixture without RAP has increased the fracture energy since the inclusion of capsules would increase the bond between asphalt binder and aggregates. In contrast, encapsulated mixtures containing RAP materials had lower fracture energy values compared with their corresponding mixtures without capsule addition. Furthermore, the results revealed that the addition of RBO capsules to the mixtures with RAP materials increased the healing performance of mixtures due to the fact that the reduced viscosity of aged asphalt binder had increased following the gradual release of the rejuvenator; therefore, the microcracks were closed and prevented further damages.
Conventional fossil-based energy sources have numerous environmental demerits; sustainable and renewable sources are attracting the undivided attention of researchers owing to their valuable physical ...and chemical features. Several industrial-scale technologies are employing hydrogen as a green energy source as the most preferential source. Not only is hydrogen a potent energy carrier but also it is not detrimental to the environment. Among many other hydrogen production processes, steam reforming of methanol (SRM) is deemed a practical method due to its low energy consumption. Cu, Ni, noble metals, etc., are the salient catalysts in SRM. Many researchers have conducted thorough studies incorporating improvement of the catalysts’ activity, mechanism predictions, and the impacts of operational parameters and reformers. This review concentrates on the SRM catalysts, supports, promoters, and the effect of the operational parameters on the process efficiency and H2 production yield. In this regard, the methanol conversion, H2 and CO selectivity, and operating parameters are notably contingent on the surface characterization and chemistry of the catalysts. Herein, Cu-, Ni-, and noble metal-based catalysts on various metal oxide supports, such as Al2O3 and ZnO, are assessed meticulously in the SRM process from the standpoint of mechanism and catalyst characterization. Most of the peer-reviewed studies had encountered agglomeration, metal particle sintering at high temperatures, coke formation, and deactivation of catalysts as the prevalent barriers. Hence, the novel methods of conquering the above-mentioned obstacles are evaluated in this review. Employment of diverse synthetic methods, bimetallic catalysts, distinct catalyst promoters, and unconventional supports, such as metal–organic frameworks, carbon nanotubes, and zeolites, are the salient routes to overcome the metal dispersion and thermal stability issues. In addition, the influence of operational parameters (temperature of the process, steam/carbon ratio, and feed flow rate) has been weighed painstakingly, along with introducing the research gap and future perspectives in the territory of SRM catalysts.
Since the beginning of the COVID-19 pandemic, new and non-invasive digital technologies such as artificial intelligence (AI) had been introduced for mortality prediction of COVID-19 patients. The ...prognostic performances of the machine learning (ML)-based models for predicting clinical outcomes of COVID-19 patients had been mainly evaluated using demographics, risk factors, clinical manifestations, and laboratory results. There is a lack of information about the prognostic role of imaging manifestations in combination with demographics, clinical manifestations, and laboratory predictors. The purpose of the present study is to develop an efficient ML prognostic model based on a more comprehensive dataset including chest CT severity score (CT-SS). Fifty-five primary features in six main classes were retrospectively reviewed for 6854 suspected cases. The independence test of Chi-square was used to determine the most important features in the mortality prediction of COVID-19 patients. The most relevant predictors were used to train and test ML algorithms. The predictive models were developed using eight ML algorithms including the J48 decision tree (J48), support vector machine (SVM), multi-layer perceptron (MLP), k-nearest neighbourhood (k-NN), Naïve Bayes (NB), logistic regression (LR), random forest (RF), and eXtreme gradient boosting (XGBoost). The performances of the predictive models were evaluated using accuracy, precision, sensitivity, specificity, and area under the ROC curve (AUC) metrics. After applying the exclusion criteria, a total of 815 positive RT-PCR patients were the final sample size, where 54.85% of the patients were male and the mean age of the study population was 57.22 ± 16.76 years. The RF algorithm with an accuracy of 97.2%, the sensitivity of 100%, a precision of 94.8%, specificity of 94.5%, F1-score of 97.3%, and AUC of 99.9% had the best performance. Other ML algorithms with AUC ranging from 81.2 to 93.9% had also good prediction performances in predicting COVID-19 mortality. Results showed that timely and accurate risk stratification of COVID-19 patients could be performed using ML-based predictive models fed by routine data. The proposed algorithm with the more comprehensive dataset including CT-SS could efficiently predict the mortality of COVID-19 patients. This could lead to promptly targeting high-risk patients on admission, the optimal use of hospital resources, and an increased probability of survival of patients.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Campylobacter, a leading cause of foodborne diseases, is well recognized worldwide. Poultry and poultry products are considered as major sites for Campylobacter infection in humans. The extensive ...uses of antibiotics mostly as growth promoters and for therapeutic purposes have led to the emergence of antibiotic-resistant strains of foodborne pathogens including Campylobacter. A key tenet of this paper is the need for reviewing the previous studies conducted around the globe on the prevalence and antimicrobial resistance of Campylobacter spp. isolates in duck to better understand the sources and trends of infection. Based on published data, the prevalence of Campylobacter spp. in duck and duck-related samples ranged from 0% to 100% and was largely influenced by the isolation method. Among Campylobacter spp., C. jejuni was the predominant cause of campylobacteriosis, followed by C. coli. Campylobacter spp. from ducks were mostly resistant to fluoroquinolones and tetracycline and a lesser extent to gentamicin, chloramphenicol, and erythromycin. Some studies showed that ducks may pose a risk for acquiring campylobacteriosis because they had genotypes quite similar to human isolates detected previously. A continued monitoring approach is needed, at national and international levels, with enhanced surveillance and reporting of trends, as well as harmonization of surveillance systems toward a one-health approach to monitoring antimicrobial resistance in animal production particularly if increased resistance rates are being demonstrated.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
High ambient temperature is a major problem in commercial broiler production in the humid tropics because high producing broiler birds consume more feed, have higher metabolic activity, and thus ...higher body heat production. To evaluate the effects of two previously isolated potential probiotic strains (Lactobacillus pentosus ITA23 and Lactobacillus acidophilus ITA44) on broilers growing under heat stress condition, a total of 192 chicks were randomly allocated into four treatment groups of 48 chickens each as follows: CL, birds fed with basal diet raised in 24 °C; PL, birds fed with basal diet plus 0.1 % probiotic mixture raised in 24 °C; CH, birds fed with basal diet raised in 35 °C; and PH, birds fed with basal diet plus 0.1 % probiotic mixture raised in 35 °C. The effects of probiotic mixture on the performance, expression of nutrient absorption genes of the small intestine, volatile fatty acids (VFA) and microbial population of cecal contents, antioxidant capacity of liver, and fatty acid composition of breast muscle were investigated. Results showed that probiotic positively affected the final body weight under both temperature conditions (PL and PH groups) compared to their respective control groups (CL and CH). Probiotic supplementation numerically improved the average daily gain (ADG) under lower temperature, but significantly improved ADG under the higher temperature (PÂ
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The
Amygdalus spinosissima
(Rosaceae) plant has been used in the Iranian folk medicine as a remedy for the burn wound. Hence, in this study, we aimed to determine the possible medicinal potential of ...the plant focusing on the root part. The bioactive phenolic and flavonoid compounds present in the root extract of the
Amygdalus spinosissima
plant as well as its antioxidant and anti-inflammatory properties were determined. Moreover, the effects of root extract on learning and memory in mice were evaluated. The results revealed that the root methanolic extract contained phenolic and flavonoid compounds including apigenin, quercetin, rutin, kaempferol, gallic acid, syringic acid, ferulic acid, and ellagic acid. The extract possessed antioxidant, acetylcholinesterase (AChE), and butyrylcholinesterase (BChE) inhibitory activities in vitro. These biological activities were attributed to the presence of phenolics and flavonoids. The
A. spinosissima
root extract improved learning and memory function in scopolamine-induced memory dysfunction in mice as determined using the Morris water maze task. The extract modulated the AChE, BChE, and inflammatory genes and enhanced the expression of the antioxidant enzymes in the brain. Consequently,
A. spinosissima
root extract could be considered as a promising source of potent bioactive compounds in the retarding the development of neurodegenerative diseases such as Alzheimer's disease.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Photocatalytic wastewater treatment and concurrent energy production or metal ions conversion to less harmful products have great potential to address both environmental and energy challenging ...issues, two of the most significant problems facing humankind. Many efforts have been devoted for achieving enhanced photocatalytic activity as well as optimizing reaction conditions and materials design. In this context, various strategies were applied to develop efficient dual-functional photocatalysts for environmental purification and simultaneous energy production. Concurrent photocatalytic degradation of organic pollutants and Cr(VI) reduction to less toxic Cr(III) improved the rate of both reactions as compared to their single process. During photocatalysis for energy production from wastewater treatment, the organic pollutant can either play as a hole scavenger or as an electron donor to increase the rate of H
2
production. Moreover, variation of reaction parameters such as pH, amount of photocatalyst, temperature, type of reactor design, amount and type of organic pollutant as well as incident light intensity on the activity of the photocatalyst during simultaneous reactions are investigated. Furthermore, the design of the photocatalyst by morphology control and engineering, metal/nonmetal modification, and semiconductor coupling exhibited a key role in improving the efficiency of the concurrent photocatalytic reactions. In addition, photocatalytic conversion of CO
2
as the primary greenhouse gas to value-added industrial chemicals such as fuels, alcohols, and other hydrocarbons is reviewed as a step toward solving the global environmental and energy challenging issues. Finally, the synergetic effect of adsorption process and photocatalysis by improving specific surface area of a photocatalyst to remove high concentration of organic pollutants from wastewater will be discussed.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Plant root symbiosis with Arbuscular mycorrhizal (AM) fungi improves uptake of water and mineral nutrients, improving plant development under stressful conditions. Unraveling the unified ...transcriptomic signature of a successful colonization provides a better understanding of symbiosis. We developed a framework for finding the transcriptomic signature of Arbuscular mycorrhiza colonization and its regulating transcription factors in roots of
. Expression profiles of roots in response to AM species were collected from four separate studies and were combined by direct merging meta-analysis. Batch effect, the major concern in expression meta-analysis, was reduced by three normalization steps: Robust Multi-array Average algorithm, Z-standardization, and quartiling normalization. Then, expression profile of 33685 genes in 18 root samples of
as numerical features, as well as study ID and Arbuscular mycorrhiza type as categorical features, were mined by seven models: RELIEF, UNCERTAINTY, GINI INDEX, Chi Squared, RULE, INFO GAIN, and INFO GAIN RATIO. In total, 73 genes selected by machine learning models were up-regulated in response to AM (Z-value difference > 0.5). Feature weighting models also documented that this signature is independent from study (batch) effect. The AM inoculation signature obtained was able to differentiate efficiently between AM inoculated and non-inoculated samples. The AP2 domain class transcription factor, GRAS family transcription factors, and cyclin-dependent kinase were among the highly expressed meta-genes identified in the signature. We found high correspondence between the AM colonization signature obtained in this study and independent RNA-seq experiments on AM colonization, validating the repeatability of the colonization signature. Promoter analysis of upregulated genes in the transcriptomic signature led to the key regulators of AM colonization, including the essential transcription factors for endosymbiosis establishment and development such as
factors. The approach developed in this study offers three distinct novel features: (I) it improves direct merging meta-analysis by integrating supervised machine learning models and normalization steps to reduce study-specific batch effects; (II) seven attribute weighting models assessed the suitability of each gene for the transcriptomic signature which contributes to robustness of the signature (III) the approach is justifiable, easy to apply, and useful in practice. Our integrative framework of meta-analysis, promoter analysis, and machine learning provides a foundation to reveal the transcriptomic signature and regulatory circuits governing Arbuscular mycorrhizal symbiosis and is transferable to the other biological settings.
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