bluuebunny/crossref_metadata_2025 huggingface dataset:
Non-Associated Flow Rule-Based Elasto-Viscoplastic Model for Clay
Authors: Islam Mohammad , Gnanendran Carthigesu
Published: June 2020

We develop a non-associated flow rule (NAFR)-based elasto-viscoplastic (EVP) model for isotropic clays. For the model formulation, we introduce the critical state soil mechanics theory (CSSMT), the bounding surface theory and Perzyna’s overstress theory. The NAFR based EVP model comprises three surfaces: the potential surface, the reference surface and the loading surface. Additionally, in the model formulation, assuming the potential surface and the reference surface are identical, we obtain the associated flow rule-based EVP model. Both EVP models require seven parameters and five of them are identical to the Modified Cam Clay model. The other two parameters are the surface shape parameter and the secondary compression index. Moreover, we introduce the shape parameter in the model formulation to control the surface shape and to account for the overconsolidation state of clay. Additionally, we incorporate the secondary compression index to introduce the viscosity of clay. Also, we validate the EVP model performances for the Shanghai clay, the San Francisco Bay Mud (SFBM) clay and the Kaolin clay. Furthermore, we use the EVP models to predict the long-term field monitoring measurement of the Nerang Broadbeach roadway embankment in Australia. From the comparison of model predictions, we find that the non-associated flow rule EVP model captures well a wide range of experimental results and field monitoring embankment data. Furthermore, we also observe that the natural clay exhibits the flow rule effect more compared to the reconstituted clay.
Determinants of Motivation among Healthcare Workers in the East African Community between 2009–2019: A Systematic Review
Authors: Muthuri Rose Nabi Deborah Karimi , Senkubuge Flavia , Hongoro Charles
Published: June 2020

Healthcare workers are an essential element in the functionality of the health system. However, the health workforce impact on health systems tends to be overlooked. Countries within the Sub-Saharan region such as the six in the East African Community (EAC) have weak and sub-optimally functioning health systems. As countries globally aim to attain Universal Health Coverage and the Sustainable Development Goal 3, it is crucial that the significant role of the health workforce in this achievement is recognized. In this systematic review, we aimed to synthesise the determinants of motivation as reported by healthcare workers in the EAC between 2009 and 2019. A systematic search was performed using four databases, namely Cochrane library, EBSCOhost, ProQuest and PubMed. The eligible articles were selected and reviewed based on the authors’ selection criteria. A total of 30 studies were eligible for review. All six countries that are part of the EAC were represented in this systematic review. Determinants as reported by healthcare workers in six countries were synthesised. Individual-level-, organizational/structural- and societal-level determinants were reported, thus revealing the roles of the healthcare worker, health facilities and the government in terms of health systems and the community or society at large in promoting healthcare workers’ motivation. Monetary and non-monetary determinants of healthcare workers’ motivation reported are crucial for informing healthcare worker motivation policy and health workforce strengthening in East Africa.
Telehealth Use among Community Health Centers and Cardio-Metabolic Health Outcomes
Authors: Baidwan Navneet Kaur , Davlyatov Ganisher , Mehta Tapan
Published: June 2020

Public health interventions to manage the cardio-metabolic syndrome (CMS) have had modest success, necessitating the expansion of telehealth services to where people live. This effort analyzes the association between telehealth provision and the management of CMS-related quality measures (hypertension, diabetes, weight assessment and related counseling, lipid therapy for coronary artery disease, and antiplatelet therapy for ischemic vascular disease) using the Uniform Data System administrative database during the period 2016–2018. A total of 523, 600, and 586 community health centers (CHCs) were documented using telehealth, out of the 1367, 1373, and 1362 total CHCs, in the respective three years. Our primary analysis showed that there was no association between telehealth use and the outcomes. A difference in difference approach that compared the CHCs which transitioned from not using it to using it with those that did not use telehealth in two consecutive years also produced null results. However, among rural areas, the odds of better managing the outcomes were greater for certain outcomes. Our study provides limited support that the adoption of telehealth is potentially beneficial in improving certain outcomes in the CHCs setting that are based in rural areas. More specificity in data regarding the nature of telehealth implementation in the CHC setting could bring clarity in these associations.
Relationship between Muscle Cross-Sectional Area by MRI and Muscle Thickness by Ultrasonography of the Triceps Surae in the Sitting Position
Authors: Miyachi Ryo , Yamazaki Toshiaki , Ohno Naoki , Miyati Tosiaki
Published: June 2020

The purpose of this study was to determine the differences in the muscle cross-sectional area (MCSA) of the triceps surae in the supine and sitting positions using magnetic resonance imaging (MRI), and the relationship between the MCSA of the triceps surae in the sitting position and muscle thickness (MT), assessed using MRI and ultrasonography, respectively. This study included 16 healthy young male participants. The measurement positions were 90° flexion of the knee joint and neutral position of the ankle joint in the sitting or supine positions. Using an open-configuration MRI system with a vertical gap and ultrasonography, we measured the MCSA and MT of the soleus muscle and the medial and lateral heads of the gastrocnemius muscle at three selected locations in the ventral part of the muscle. As a result, the 50% portion of the soleus muscle and the 25% and 50% portions of the gastrocnemius medial and lateral heads were higher in the sitting position than in the supine position. Furthermore, only 50% of the gastrocnemius medial head showed a correlation between the MCSA and MT. When using the MT of the triceps surae as an indicator of muscle volume in the sitting position, the muscle site should be considered.
Tropical PeatLand Forest Biomass Estimation Using Polarimetric Parameters Extracted from RadarSAT-2 Images
Authors: Waqar Mirza , Sukmawati Rahmi , Ji Yaqi , Sri Sumantyo Josaphat
Published: June 2020

This paper was aimed at estimating the forest aboveground biomass (AGB) in the Central Kalimantan tropical peatland forest, Indonesia, using polarimetric parameters extracted from RadarSAT-2 images. Six consecutive acquisitions of RadarSAT-2 full polarimetric data were acquired and polarimetric parameters were extracted. The backscattering coefficient ( σ o ) for HH, HV, VH, and VV channels was computed respectively. Entropy (H) and alpha ( α ) were computed using eign decomposition. In order to understand the scattering behavior, Yamaguchi decomposition was performed to estimate surface scattering ( γ s u r f ) and volume scattering ( γ v o l ) components. Similarly following polarimetric indices were computed; Biomass Index (BMI), Canopy Structure Index (CSI), Volume Scattering Index (VSI), Radar Vegetation Index (RVI) and Pedestal Height ( p h ). The PolSAR parameters were evaluated in terms of their temporal consistency, inter-dependence, and suitability for forest aboveground biomass estimation across rainy and dry conditions. Regression analysis was performed between referenced biomass measurements and polarimetric parameters; VSI, H, RVI, p h , and γ v o l were found significantly correlated with AGB. Biomass estimation was carried out using significant models. Resultant models were validated using field-based AGB measurements. Validation results show a significant correlation between measured and referenced biomass measurements with temporal consistency over the acquisition time period.
On the Potential of Silicon as a Building Block for Life
Authors: Petkowski Janusz Jurand , Bains William , Seager Sara
Published: June 2020

Despite more than one hundred years of work on organosilicon chemistry, the basis for the plausibility of silicon-based life has never been systematically addressed nor objectively reviewed. We provide a comprehensive assessment of the possibility of silicon-based biochemistry, based on a review of what is known and what has been modeled, even including speculative work. We assess whether or not silicon chemistry meets the requirements for chemical diversity and reactivity as compared to carbon. To expand the possibility of plausible silicon biochemistry, we explore silicon’s chemical complexity in diverse solvents found in planetary environments, including water, cryosolvents, and sulfuric acid. In no environment is a life based primarily around silicon chemistry a plausible option. We find that in a water-rich environment silicon’s chemical capacity is highly limited due to ubiquitous silica formation; silicon can likely only be used as a rare and specialized heteroatom. Cryosolvents (e.g., liquid N2) provide extremely low solubility of all molecules, including organosilicons. Sulfuric acid, surprisingly, appears to be able to support a much larger diversity of organosilicon chemistry than water.
Serum and Plasma Tumor Necrosis Factor Alpha Levels in Individuals with Obstructive Sleep Apnea Syndrome: A Meta-Analysis and Meta-Regression
Authors: Imani Mohammad Moslem , Sadeghi Masoud , Khazaie Habibolah , Emami Mehrdad , Sadeghi Bahmani Dena , Brand Serge
Published: June 2020

Background: Obstructive sleep apnea syndrome (OSAS) is associated with a variety of inflammatory factors. Specifically, proinflammatory cytokines appear to be associated with the pathogenesis of OSAS. Methods: For the present meta-analysis and meta-regression on serum and plasma tumor necrosis factor alpha (TNF-α) levels in individuals with and without OSAS, we performed a systematic search without any restrictions of the PubMed/Medline, Scopus, Cochrane Library, and Web of Science databases to find relevant articles published up to 1 February 2020. Results: Fifty-five (adults: 29 studies on serum and 17 studies on plasma; children: 4 studies on serum and 5 studies on plasma) were included and analyzed. Always compared to age-matched healthy controls, the pooled MDs were as follows: adults, serum: 10.22 pg/mL (95% CI = 8.86, 11.58; p < 0.00001); adults, plasma: 5.90 pg/mL (95% CI = 4.00, 7.80; p < 0.00001); children, serum: 0.21 pg/mL (95% CI = 0.05, 0.37; p = 0.01); children, plasma: 5.90 pg/mL (95% CI = 4.00, 7.80; p < 0.00001). Conclusions: Compared to healthy and age-matched controls, adult individuals with OSAS had significantly higher serum/plasma TNF-α levels. For children with OSAS, significantly higher levels were observed for TNF-α in serum but not in plasma.
On the Analysis of New COVID-19 Cases in Pakistan Using an Exponentiated Version of the M Family of Distributions
Authors: Bantan Rashad A. R. , Chesneau Christophe , Jamal Farrukh , Elgarhy Mohammed
Published: June 2020

This paper develops the exponentiated Mfamily of continuous distributions, aiming to provide new statistical models for data fitting purposes. It stands out from the other families, as it depends on two baseline distributions, with the use of ratio and power transforms in the definition of the main cumulative distribution function. Thanks to the joint action of the possibly different baseline distributions, flexible statistical models can be created, motivating a complete study in this regard. Thus, we discuss the theoretical properties of the new family, with emphasis on those of potential interest to the overall probability and statistics. Then, a new three-parameter lifetime distribution is derived, with the choices of the inverse exponential and exponential distributions as baselines. After pointing out the great flexibility of the related model, we apply it to analyze an actual dataset of current interest: the daily COVID-19 cases observed in Pakistan from 21 March to 29 May 2020 (inclusive). As notable results, we demonstrate that the proposed model is the best among the 15 top ranked models in the literature, including the inverse exponential and exponential models, several modern extensions of them depending on more parameters, and the “unexponentiated” version of the proposed model as well. As future perspectives, the proposed model can be of interest to analyze data on COVID-19 cases in other countries, for possible comparison studies.
Strong Convergence of Mann’s Iteration Process in Banach Spaces
Authors: Xu Hong-Kun , Altwaijry Najla , Chebbi Souhail
Published: June 2020

Mann’s iteration process for finding a fixed point of a nonexpansive mapping in a Banach space is considered. This process is known to converge weakly in some class of infinite-dimensional Banach spaces (e.g., uniformly convex Banach spaces with a Fréchet differentiable norm), but not strongly even in a Hilbert space. Strong convergence is therefore a nontrivial problem. In this paper we provide certain conditions either on the underlying space or on the mapping under investigation so as to guarantee the strong convergence of Mann’s iteration process and its variants.
Mathematical Model for Production Plan Optimization—A Case Study of Discrete Event Systems
Authors: Rezig Sadok , Ezzeddine Wajih , Turki Sadok , Rezg Nidhal
Published: June 2020

This paper proposes an optimal scheduling model under production and maintenance constraints for a real case of a discrete event system. The intent was to use the rich mathematical theory and algorithms of optimization in the study of this important class of systems. The current study detailed firstly a new approach for mapping a simulation event relationship graph into a mixed-integer program, with a flexible workshop real case. Several other potential applications of the mathematical model are examined, thanks to the model constraints flexibility characteristics, including a general case of a manufacturing system for optimal resource scheduling, an application on the case of hospital beds’ management. The model extension could be also interesting for other applications like museum systems or the case of big data in complex and social networks.
The Transmuted Odd Fréchet-G Family of Distributions: Theory and Applications
Authors: Badr Majdah M. , Elbatal Ibrahim , Jamal Farrukh , Chesneau Christophe , Elgarhy Mohammed
Published: June 2020

The last years, the odd Fréchet-G family has been considered with success in various statistical applications. This notoriety can be explained by its simple and flexible exponential-odd structure quite different to the other existing families, with the use of only one additional parameter. In counter part, some of its statistical properties suffer of a lack of adaptivity in the sense that they really depend on the choice of the baseline distribution. Hence, efforts have been made to relax this subjectivity by investigating extensions or generalizations of the odd transformation at the heart of the construction of this family, with the aim to reach new perspectives of applications as well. This study explores another possibility, based on the transformation of the whole cumulative distribution function of this family (while keeping the odd transformation intact), through the use of the quadratic rank transmutation that has proven itself in other contexts. We thus introduce and study a new family of flexible distributions called the transmuted odd Fréchet-G family. We show how the former odd Fréchet-G family is enriched by the proposed transformation through theoretical and practical results. We emphasize the special distribution based on the standard exponential distribution because of its desirable features for the statistical modeling. In particular, different kinds of monotonic and nonmonotonic shapes for the probability density and hazard rate functions are observed. Then, we show how the new family can be used in practice. We discuss in detail the parametric estimation of a special model, along with a simulation study. Practical data sets are handle with quite favorable results for the new modeling strategy.
A Hybrid Predictive Approach for Chromium Layer Thickness in the Hard Chromium Plating Process Based on the Differential Evolution/Gradient Boosted Regression Tree Methodology
Authors: Garcia Nieto Paulino José , García Gonzalo Esperanza , Sanchez Lasheras Fernando , Bernardo Sánchez Antonio
Published: June 2020

The purpose of the industrial process of chromium plating is the creation of a hard and wear-resistant layer of chromium over a metallic surface. One of the main properties of chromium plating is its resistance to both wear and corrosion. This research presents an innovative nonparametric machine learning approach that makes use of a hybrid gradient boosted regression tree (GBRT) methodology for hard chromium layer thickness prediction. GBRT is a non-parametric statistical learning technique that produces a prediction model in the form of an ensemble of weak prediction models. The motivation for boosting is a procedure that combines the output of many weak classifiers to produce a powerful committee. In this study, the GBRT hyperparameters were optimized with the help of differential evolution (DE). DE is an optimization technique within evolutionary computing. The results found that this model was able to predict the thickness of the chromium layer formed in this industrial process with a determination coefficient equal to 0.9842 and a root-mean-square error value of 0.01590. The two most important variables of the model were the time of the hard-chromium process and the thickness of the layer removed by electropolishing. Thus, these results provide a foundation for an accurate predictive model of hard chromium layer thickness. The derived model also allowed the ranking of the importance of the independent input variables that were examined. Finally, the high performance and simplicity of the model make the DE/GBRT method attractive compared to conventional forecasting techniques.
Interval Grey Prediction Models with Forecast Combination for Energy Demand Forecasting
Authors: Jiang Peng , Hu Yi-Chung , Wang Wenbao , Jiang Hang , Wu Geng
Published: June 2020

Time series data for decision problems such as energy demand forecasting are often derived from uncertain assessments, and do not meet any statistical assumptions. The interval grey number becomes an appropriate representation for an uncertain and imprecise observation. In order to obtain nonlinear interval grey numbers with better forecasting accuracy, this study proposes a combined model by fusing interval grey numbers estimated by neural networks (NNs) and the grey prediction models. The proposed model first uses interval regression analysis using NNs to estimate interval grey numbers for a real valued sequence; and then a grey residual modification model is constructed using the upper and lower wrapping sequences obtained by NNs. It turns out that two different kinds of interval grey numbers can be estimated by nonlinear interval regression analysis. Forecasting accuracy on real data sequences was then examined by the best non-fuzzy performance values of the combined model. The proposed combined model performed well compared with the other interval grey prediction models considered.
Method for Developing Combinatorial Generation Algorithms Based on AND/OR Trees and Its Application
Authors: Shablya Yuriy , Kruchinin Dmitry , Kruchinin Vladimir
Published: June 2020

In this paper, we study the problem of developing new combinatorial generation algorithms. The main purpose of our research is to derive and improve general methods for developing combinatorial generation algorithms. We present basic general methods for solving this task and consider one of these methods, which is based on AND/OR trees. This method is extended by using the mathematical apparatus of the theory of generating functions since it is one of the basic approaches in combinatorics (we propose to use the method of compositae for obtaining explicit expression of the coefficients of generating functions). As a result, we also apply this method and develop new ranking and unranking algorithms for the following combinatorial sets: permutations, permutations with ascents, combinations, Dyck paths with return steps, labeled Dyck paths with ascents on return steps. For each of them, we construct an AND/OR tree structure, find a bijection between the elements of the combinatorial set and the set of variants of the AND/OR tree, and develop algorithms for ranking and unranking the variants of the AND/OR tree.
Expression and Characterization of an Alginate Lyase and Its Thermostable Mutant in Pichia pastoris
Authors: Yang Suxiao , Liu Zhemin , Fu Xiaodan , Zhu Changliang , Kong Qing , Yang Min , Mou Haijin
Published: June 2020

Alginate is one of the most abundant polysaccharides in algae. Alginate lyase degrades alginate through a β-elimination mechanism to produce alginate oligosaccharides with special bioactivities. Improving enzyme activity and thermal stability can promote the application of alginate lyase in the industrial preparation of alginate oligosaccharides. In this study, the recombinant alginate lyase cAlyM and its thermostable mutant 102C300C were expressed and characterized in Pichia pastoris. The specific activities of cAlyM and 102C300C were 277.1 U/mg and 249.6 U/mg, respectively. Both enzymes showed maximal activity at 50 °C and pH 8.0 and polyG preference. The half-life values of 102C300C at 45 °C and 50 °C were 2.6 times and 11.7 times the values of cAlyM, respectively. The degradation products of 102C300C with a lower degree of polymerization contained more guluronate. The oligosaccharides with a polymerization degree of 2–4 were the final hydrolytic products. Therefore, 102C300C is potentially valuable in the production of alginate oligosaccharides with specific M/G ratio and molecular weights.
Synthesis and Biological Evaluation of Diversified Hamigeran B Analogs as Neuroinflammatory Inhibitors and Neurite Outgrowth Stimulators
Authors: Li Ruo-Xin , Han Rui , Wu Guo-Jie , Han Fu-She , Gao Jin-Ming
Published: June 2020

We describe the efficient synthesis of a series of new simplified hamigeran B and 1-hydroxy-9-epi-hamigeran B norditerpenoid analogs (23 new members in all), structurally related to cyathane diterpenoid scaffold, and their anti-neuroinflammatory and neurite outgrowth-stimulating (neurotrophic) activity. Compounds 9a, 9h, 9o, and 9q exhibited moderate nerve growth factor (NGF)-mediated neurite-outgrowth promoting effects in PC-12 cells at the concentration of 20 μm. Compounds 9b, 9c, 9o, 9q, and 9t showed significant nitric oxide (NO) production inhibition in lipopolysaccharide (LPS)-activated BV-2 microglial cells, of which 9c and 9q were the most potent inhibitors, with IC50 values of 5.85 and 6.31 μm, respectively. Two derivatives 9q and 9o as bifunctional agents displayed good activities as NO production inhibitors and neurite outgrowth-inducers. Cytotoxicity experiments, H2O2-induced oxidative injury assay, and ELISA reaction speculated that compounds may inhibit the TNF-α pathway to achieve anti-inflammatory effects on nerve cells. Moreover, molecular docking studies provided a better understanding of the key structural features affecting the anti-neuroinflammatory activity and displayed significant binding interactions of some derivatives (like 9c, 9q) with the active site of iNOS protein. The structure-activity relationships (SARs) were also discussed. These results demonstrated that this structural class compounds offered an opportunity for the development of a new class of NO inhibitors and NGF-like promotors.
Incidence of Prostate Cancer in Inflammatory Bowel Disease: A Meta-Analysis
Authors: Carli Edoardo , Caviglia Gian Paolo , Pellicano Rinaldo , Fagoonee Sharmila , Rizza Stefano , Astegiano Marco , Saracco Giorgio Maria , Ribaldone Davide Giuseppe
Published: June 2020

Background and objectives: Inflammatory bowel disease (IBD) is associated with an increased risk of developing colorectal cancer as well as some extra-intestinal tumors, but there are still limited data about the risk of prostate cancer (PC). To analyze if there is an increased risk of PC in patients affected by IBD, we performed a systematic review with meta-analysis. Materials and Methods: A Pubmed search of all studies comparing standardized incidence ratio (SIR) or odds ratio (OR) or relative risks (RR) of PC between IBD and non IBD groups, published until March 2020 was conducted. The study protocol was registered on PROSPERO. Twelve studies, mostly population studies, were included. The quality score of these studies, evaluated by the Newcastle–Ottawa Scale, was 7. The heterogeneity was high among the studies in which ulcerative colitis (UC) was considered separate from Crohn’s disease (CD) and in the studies that considered UC and CD together (“IBD-studies”), while it was low in the studies which considered CD separate from UC. Results: The relative risk of developing PC was 1.71 (95% confidence interval [CI] 1.16–2.51, p = 0.007) in IBD, 1.10 (95%CI 0.98–1.25, p = 0.116) in CD, and 1.22 (95%CI 0.98–1.51, p = 0.07) in UC. Conclusions: Patients with IBD appear to have a slightly increased risk of PC compared to the general population.
Analysis of Diabetes Mellitus-Related Amputations in the State of Espírito Santo, Brazil
Authors: Costa Wendel Jose Teixeira , Penha-Silva Nilson , Bezerra Italla Maria Pinheiro , Paulo dos Santos Ismar , Ramos José Lucas Souza , Castro Jonathan Mendes de , Pereira Júlio Eduardo Gomes , Silva Alan Patrício da , Monteiro Adilson , de Abreu Luiz Carlos
Published: June 2020

Background and objectives: Diabetes mellitus (DM) stands out among the most important public health problems worldwide since it represents a high burden on health systems and is associated with higher hospitalization rates, and a higher incidence of cardiovascular diseases. Amputations are among the most common complications, leading to disability and increasing care costs. This research aims to analyze the prevalence of DM-related amputations, comorbidities and associated risk factors in the diabetic population residing in the State of Espírito Santo, Brazil. Materials and Methods: This is a quantitative, exploratory, cross-sectional study with a time series design and the use of secondary data registered and followed by the system of Registration and Monitoring of Hypertension and Diabetes—SisHiperdia. Results: The sample consisted of 64,196 diabetic patients, out of them, 3.9% had type 1 DM, 10.9% with type 2 DM, and 85.2% with DM coexisting with hypertension. Most were female (66.6%), aged 40 to 59 years (45.6%), and 60 years and older (45.2%). The prevalence of DM-related amputations in the analyzed sample was 1.2% in type 1 DM, 1.5% in type 2 DM, and 2.2% in concomitant DM and hypertension. Higher amputation rates were observed in males in the age group above 60 years in type 1 DM and type 2 DM and were slightly higher in the age groups up to 29 years in DM with hypertension. A higher prevalence of amputation was related to smoking, physical inactivity, acute myocardial infarction (AMI), stroke, chronic kidney disease (CKD), and diabetic foot (DF) in all types of DM. Conclusions: The present study showed a significant prevalence of DM-related amputations. An increased prevalence was evidenced when correlated with smoking, physical inactivity, AMI, stroke, CKD, and DF with significant statistical associations, except for a sedentary lifestyle in type 1 DM.
Effects of Second-Phase Particles on Microstructure Evolution in Mg-2Zn Based Magnesium Alloys during Annealing Treatment
Authors: Zhang Yun , Jiang Haitao , Wang Yujiao , Xu Zhe
Published: June 2020

As an important fabrication process, annealing treatment is conducted to eliminate distortion in magnesium alloy sheets. Second-phase particles can provide nucleation sites for recrystallization grains, and the basal texture is related to the recrystallization behavior. Three experimental Mg-2Zn-based magnesium alloy sheets were investigated by the salt bath annealing process. Combined with variations in hardness softening, evolution of microstructure and basal texture, the effect of second-phase particles on microstructure evolution was analyzed. The results showed that the significant influence of size and distribution of second-phase particles on static recrystallization in magnesium alloy sheets was exhibited, which lead to the formation of two stages in the annealing process, combined with static recovery behavior. Second phase particles with coarse size were beneficial to recrystallization grains’ nucleation and increased recrystallization behavior in the initial stage of annealing. Second-phase particles with fine size inhibited recrystallization behavior and weakened the softening of hardness. The basal texture was weakened by second phase particles at the stage of recrystallization nucleation. The change in basal texture at the stage of grain growth was related to the size of second-phase particles. The regulation of basal texture enhancement can be envisioned by modifying second-phase particles.
Springback Prediction of Dieless Forming of AZM120 Sheet Metal Based on Constitutive Model
Authors: Wu Zijin , Gong Junjie , Chen Yangdong , Wang Jinrong , Wei Yuanyuan , Gao Jianhe
Published: June 2020

Springback control is a key issue of the sheet-metal-forming process. In this paper, the mechanism of sheet-metal-forming along the folding trajectory of the computer numerical control (CNC) four-side automatic panel bender was studied, based on the bend-forming springback compensation theory of the power function material model. Firstly, the mechanical property of AZM120 sheet metal standard samples was tested. Then, a theoretical model of springback compensation under plane strain conditions was built, based on the constitutive relationship of the elastic or the elastic-plastic power hardening material. In addition, a sheet-metal-forming trajectory model was designed for sheet metal bending using the vector method. Finally, a laser tracker was used to acquire the folding trajectory, and then the reliability of the trajectory model was verified. On this basis, the influences of geometric and process parameters, such as sheet thickness, forming angle, and bending radius in springback control, were studied according to the theoretical formula and verified by experiments. The proposed method is generally applicable to operation conditions where the bending radius ranges between 1.5 and 6.0 mm and plate thickness ranges from 0.8 to 2.5 mm, and the achieved overall accuracy was more than 89%.
Improved Atomization via a Mechanical Atomizer with Optimal Geometric Parameters and an Air-Assisted Component
Authors: Levitsky Inna , Tavor Dorith
Published: June 2020

Atomization of liquid media is a key aim in various technological disciplines, and solutions that improve spray performance, while decreasing energy consumption, are in great demand. That concept is very important in the development of liquid fuel spray atomizers in high-efficiency microturbines and other generator systems with low inlet pressure and a wide range of power supply. Here we present a study of the liquid atomization characteristics for a new mechanical atomizer that has optimal geometric parameters and a preliminary swirl stage. In our air-assisted atomizer, air is introduced through a swirl chamber positioned at the exit of the mechanical atomizer. The optimized mechanical atomizer alone can achieve D32 drop diameters in the range of 80 to 40 µm at water supply pressures of 2 to 5 bar, respectively. The addition of an air swirl chamber substantially decreases drop sizes. At an air–liquid ratio (ALR) equal to 1, water pressures of 2.5 to 3 bar and air supply pressures 0.35 to 1 bar, D32 drops with diameters of 20–30 µm were obtained. In an air-assisted atomizer the parameters of the mechanical atomizer have a much stronger influence on drop diameters than do characteristics of the air-swirl chamber. Using a mechanical atomizer with optimal geometrical dimensions allows limiting the liquid supply pressure to 5 bar; but when an air-assisted component is introduced we can recommend an ALR ≈ 1 and an air supply pressure of up to 1 bar.
An Overview of the Elusive Passenger in the Gastrointestinal Tract of Cattle: The Shiga Toxin Producing Escherichia coli
Authors: Sapountzis Panagiotis , Segura Audrey , Desvaux Mickaël , Forano Evelyne
Published: June 2020

For approximately 10,000 years, cattle have been our major source of meat and dairy. However, cattle are also a major reservoir for dangerous foodborne pathogens that belong to the Shiga toxin-producing Escherichia coli (STEC) group. Even though STEC infections in humans are rare, they are often lethal, as treatment options are limited. In cattle, STEC infections are typically asymptomatic and STEC is able to survive and persist in the cattle GIT by escaping the immune defenses of the host. Interactions with members of the native gut microbiota can favor or inhibit its persistence in cattle, but research in this direction is still in its infancy. Diet, temperature and season but also industrialized animal husbandry practices have a profound effect on STEC prevalence and the native gut microbiota composition. Thus, exploring the native cattle gut microbiota in depth, its interactions with STEC and the factors that affect them could offer viable solutions against STEC carriage in cattle.
A Comparative Study on Trichoderma harzianum and a Combination of Candida/Bacillus as Tools for the Bioremediation of Table Olive Processing Water
Authors: Campaniello Daniela , Carlucci Antonia , Speranza Barbara , Raimondo Maria Luisa , Cibelli Francesca , Rosaria Corbo Maria , Bevilacqua Antonio
Published: June 2020

A comparative study was performed on Trichoderma harzianum and a combination of Candida boidinii/Bacillus pumilus to reduce the polluting effect of TOPW (Table Olive Processing Water) from the Spanish style. A 2k fractional design was used to study the effect of pH (6–11 for the fungus and 6–9 for Candida/Bacillus), temperature (10–35 °C) and duration (7–14 days for Candida/Bacillus and 14–21 days for T. harzianum), and the effect on phenol reduction, COD and color was evaluated. The experiments were also performed on diluted TOPW (dilution ratio 1:1). Generally, Trichoderma removed higher amounts of phenols and reduced COD more than the combination Candida/Bacillus, thus confirming the higher efficiency of filamentous fungi reported in the literature. The dilution of TOPW had an effect only on COD reduction; however, the effect was mild, at least for T. harzianum (4%), while yield increase was 9% for Bacillus/Candida. pH acted in a different way on phenol removal and COD reduction; an increase of pH caused a reduction of efficiency for COD, while the effect was positive for phenols.
Methane Production in Soil Environments—Anaerobic Biogeochemistry and Microbial Life between Flooding and Desiccation
Authors: Conrad Ralf
Published: June 2020

Flooding and desiccation of soil environments mainly affect the availability of water and oxygen. While water is necessary for all life, oxygen is required for aerobic microorganisms. In the absence of O2, anaerobic processes such as CH4 production prevail. There is a substantial theoretical knowledge of the biogeochemistry and microbiology of processes in the absence of O2. Noteworthy are processes involved in the sequential degradation of organic matter coupled with the sequential reduction of electron acceptors, and, finally, the formation of CH4. These processes follow basic thermodynamic and kinetic principles, but also require the presence of microorganisms as catalysts. Meanwhile, there is a lot of empirical data that combines the observation of process function with the structure of microbial communities. While most of these observations confirmed existing theoretical knowledge, some resulted in new information. One important example was the observation that methanogens, which have been believed to be strictly anaerobic, can tolerate O2 to quite some extent and thus survive desiccation of flooded soil environments amazingly well. Another example is the strong indication of the importance of redox-active soil organic carbon compounds, which may affect the rates and pathways of CH4 production. It is noteworthy that drainage and aeration turns flooded soils, not generally, into sinks for atmospheric CH4, probably due to the peculiarities of the resident methanotrophic bacteria.
Linking Shifts in Bacterial Community Composition and Function with Changes in the Dissolved Organic Matter Pool in Ice-Covered Baiyangdian Lake, Northern China
Authors: Zhou Shilei , Sun Yue , Yu Minghui , Shi Zhenpeng , Zhang Hang , Peng Ruizhe , Li Zaixing , Cui Jiansheng , Luo Xiao
Published: June 2020

The relationship between CDOM (Chromophoric dissolved organic matter) and the bacterial community was investigated in ice-covered Baiyangdian Lake. The results showed that environmental parameters significantly differed in Baiyangdian Lake, whereas a-diversity was not significantly different. Moreover, the microbial and functional communities exhibited significant differences, and T (Temperature), pH, ORP (Oxidation-reduction potential), DO (Dissolved oxygen), NO3−-N, NH4+-N, and Mn (Manganese) were the main environmental factors of these differences, based on redundancy analysis and the Mantel test. Biomarkers of the microbial and functional communities were investigated through linear discriminant analysis effect size and STAMP analysis. The number of biomarkers in the natural area was highest among the typical zones, and most top functions were related to carbohydrate metabolism. Two protein-like components (C1 and C2) and one humic-like component (C3) were identified by parallel factor analysis, and C1 was positively related to C2 (R = 0.99, p < 0.001), indicating the same sources. Moreover, CDOM significantly differed among the typical zones (p < 0.001). The high biological index, fluorescence index, β:α, and low humification index indicated a strong autochthonous component and aquatic bacterial origin, which was consistent with the results of UV-vis absorption spectroscopy. Network analysis revealed non-random co-occurrence patterns. The bacterial and functional communities interacted closely with CDOM. The dominant genera were CL500-29_marine_group, Flavobacterium, Limnohabitans, and Candidatus_Aquirestis. Random forest analysis showed that C1, C2, and C3 are important predictors of α- and β-diversity in the water bacterial community and its functional composition. This study provides insight into the interaction between bacterial communities and DOM (Dissolved organic matter) in ice-covered Baiyangdian Lake.
Influence of Resistance-Inducing Chemical Elicitors against Pine Wilt Disease on the Rhizosphere Microbiome
Authors: Mannaa Mohamed , Han Gil , Jeon Hee Won , Kim Junheon , Kim Namgyu , Park Ae Ran , Kim Jin-Cheol , Seo Young-Su
Published: June 2020

Pine wilt disease (PWD) caused by Bursaphelenchus xylophilus is a major threat to pine forests worldwide. Induction of resistance is a promising and safe management option that should be investigated in relation to its possible influence on the pine tree ecosystem, including the surrounding microbial communities. In this study, two main resistance-inducing chemical elicitors, methyl salicylic acid (MeSA) and acibenzolar-s-methyl (ASM), were tested for their control efficiency against PWD and their influence on the rhizosphere microbial composition. Foliar treatment of pine seedlings with the chemical elicitors resulted in a reduction in PWD severity, with ASM showing better control efficacy, reaching up to 73% compared to the untreated control. Moreover, bacterial community analysis of the rhizosphere revealed significant changes in several microbial taxa that were present at low relative abundance. In particular, ASM treatment resulted in a significant increase in specific microbial taxa, including members of the Rhodanobacter, Devosia, Bradyrhizobium, Acidibacter, Mesorhizobium, and Hyphomicrobium genera, which are known to play ecological and plant growth-promoting roles. Furthermore, chitinolytic bacteria were shown to be reduced in response to treatment with both MeSA and ASM. Altogether, the present findings demonstrate the occurrence of significant alterations in several ecologically important microbial taxa after treatment with resistance-inducing chemicals. As compared to MeSA treatment, ASM treatment was more effective at suppressing PWD and resulted in more beneficial changes in rhizosphere microbial composition.
Next-Generation Sequencing of the Whole Bacterial Genome for Tracking Molecular Insight into the Broad-Spectrum Antimicrobial Resistance of Helicobacter pylori Clinical Isolates from the Democratic Republic of Congo
Authors: Tshibangu-Kabamba Evariste , Ngoma-Kisoko Patrick de Jesus , Tuan Vo Phuoc , Matsumoto Takashi , Akada Junko , Kido Yasutoshi , Tshimpi-Wola Antoine , Tshiamala-Kashala Pascal , Ahuka-Mundeke Steve , Mumba Ngoy Dieudonné , Disashi-Tumba Ghislain , Yamaoka Yoshio
Published: June 2020

Antimicrobial susceptibility testing (AST) is increasingly needed to guide the Helicobacter pylori (H. pylori) treatment but remains laborious and unavailable in most African countries. To assess the clinical relevance of bacterial whole genome sequencing (WGS)-based methods for predicting drug susceptibility in African H. pylori, 102 strains isolated from the Democratic Republic of Congo were subjected to the phenotypic AST and next-generation sequencing (NGS). WGS was used to screen for the occurrence of genotypes encoding antimicrobial resistance (AMR). We noted the broad-spectrum AMR of H. pylori (rates from 23.5 to 90.0%). A WGS-based method validated for variant discovery in AMR-related genes (discovery rates of 100%) helped in identifying mutations of key genes statistically related to the phenotypic AMR. These included mutations often reported in Western and Asian populations and, interestingly, several putative AMR-related new genotypes in the pbp1A (e.g., T558S, F366L), gyrA (e.g., A92T, A129T), gyrB (e.g., R579C), and rdxA (e.g., R131_K166del) genes. WGS showed high performance for predicting AST phenotypes, especially for amoxicillin, clarithromycin, and levofloxacin (Youden’s index and Cohen’s Kappa > 0.80). Therefore, WGS is an accurate alternative to the phenotypic AST that provides substantial decision-making information for public health policy makers and clinicians in Africa, while providing insight into AMR mechanisms for researchers.
Complete Genome of Isoprene Degrading Nocardioides sp. WS12
Authors: Gibson Lisa , Larke-Mejía Nasmille L. , Murrell J. Colin
Published: June 2020

Isoprene is a climate-active gas whose wide-spread global production stems mostly from terrestrial plant emissions. The biodegradation of isoprene is carried out by a number of different bacteria from a wide range of environments. This study investigates the genome of a novel isoprene degrading bacterium Nocardioides sp. WS12, isolated from soil associated with Salix alba (Willow), a tree known to produce high amounts of isoprene. The Nocardioides sp. WS12 genome was fully sequenced, revealing the presence of a complete isoprene monooxygenase gene cluster, along with associated isoprene degradation pathway genes. Genes associated with rubber degradation were also present, suggesting that Nocardioides sp. WS12 may also have the capacity to degrade poly-cis-1,4-isoprene.
An Assessment of the Glyconutrient Ambrotose™ on Immunity, Gut Health, and Safety in Men and Women: A Placebo-Controlled, Double-Blind, Randomized Clinical Trial
Authors: Bloomer Richard J. , Butawan Matthew , van der Merwe Marie , Keating Faith H.
Published: June 2020

Background: Certain dietary fibers have been reported to improve gut health and cellular immunity. Ambrotose is a glyconutrient supplement that contains mannose-rich polysaccharides (acemannan), reported to improve immune function. A more nutrient-dense version of this dietary supplement has been developed recently, with added aloe leaf gel powder (acemannan). The purpose of this study was to evaluate the impact of the traditional and newly developed Ambrotose products on immunity, gut health, and psychological well-being in healthy men and women. Methods: Seventy-five men and women were randomly assigned in double-blind manner to one of five treatments, as follows: Ambrotose Advanced (AA) at 2 or 4 g daily, Ambrotose LIFE (AL) at 2 or 4 g daily, or placebo. Subjects ingested their assigned treatment daily for eight weeks. Resting heart rate, blood pressure, and measures of psychological well-being were analyzed before and after four and eight weeks of supplementation. Blood samples were collected at the same times and analyzed for zonulin, hematology measures, and cytokines—IL-6, IL-10, IL-1β, and TNF-α (analyzed both with and without stimulation via lipopolysaccharide [LPS]). Results: All Ambrotose treatments were well-tolerated. There were no differences among treatments in heart rate or blood pressure across time. Self-reported well-being scores were generally higher for the Ambrotose treatments but there were no changes of statistical significance across time (p > 0.05). Differences of statistical significance were noted for select biochemical variables, the most notable being a dramatic decrease in monocytes in the Ambrotose groups. No change was noted in the cytokine response to LPS stimulation in all groups, indicating a maintenance of a healthy immune response. Conclusion:Regular supplementation with Ambrotose is safe and can improve subclinical cellular adversity (as evidenced by a decrease in monocytes), without unnecessary activation of an immune response.
Mycosis Is a Disease State Encountered Rarely in Shore Crabs, Carcinus maenas
Authors: Davies Charlotte E. , Malkin Sophie H. , Thomas Jessica E. , Batista Frederico M. , Rowley Andrew F. , Coates Christopher J.
Published: June 2020

There is a paucity of knowledge regarding the diversity and impact(s) of disease-causing fungi in marine animals, especially shellfish. In efforts to address this knowledge gap for the shore crab Carcinus maenas, a year-long disease screen was carried out across two sites in Swansea Bay (Wales, UK) with a view to characterising putative fungal infections. Crabs were sampled between November 2017 and October 2018, and screened systematically for disease signatures using haemolymph (blood) preparations, targeted PCR and tissue histopathology. Strikingly, mycosis was confirmed in ~0.4% of total crabs tested (n = 1191) and restricted to one location only (Mumbles Pier). Clinical infections were observed in four out of four infected crabs. In these animals, the gills and hepatopancreas were congested with fungal morphotypes. In addition, some evidence indicates haemocyte (immune cell) reactivity toward the fungi. Phylogenetic placement of the partial internal transcribed spacer (ITS1) gene regions amplified from three mycotic crabs revealed the causative agent to be related to hypocrealean fungi, thereby representing a novel species.