bluuebunny/crossref_metadata_2025 huggingface dataset:
Design of personalized recommendation system for online learning resources based on improved collaborative filtering algorithm
Authors: Gan Baiqiang , Zhang Chi
Published: December 2020

In recent years, under the guidance of the educational concept of equality and sharing, universities at home and abroad have increased the development and application of online course learning resources. In China, online open courses are open to all learners on the platform of major portals. Due to the increasing number of online courses, it is increasingly difficult for learners to find the content they are interested in on the website. In addition, the traditional collaborative filtering has the problems of sparse data, cold start, and low accuracy of recommendation results, etc. Therefore, the personalized recommendation system studied in this paper adds the collaborative filtering recommendation technology of user and project attributes. The recommendation system can actively discover the interest of learners according to their behavior characteristics, and provide them with online learning resources of interest, and improve the accuracy of the recommendation results by improving the collaborative filtering algorithm. In this paper, personalized recommendation technology is applied to online course website, aiming at providing personalized, automated and intelligent recommendation system for online learners.
Controlling shareholder share pledging and Enterprise Cost Stickiness: Evidence from Chinese Firms
Authors: Li Ziyang , Zhang Yingyue , Tan Xiaohan , Yu Wen
Published: December 2020

Using a sample of Chinese enterprises pledge during the period 2008-2017, this paper investigates the cost management behavior of enterprises during the pledge period of major shareholders’ stock rights. Our findings show that with the increase of the equity pledge rate, the cost stickiness of enterprises is enhanced. Further analysis shows that the behavior that the controlling shareholder invests the equity pledge funds to a third party weakens the cost stickiness of the enterprise. We further contribute to the literature on sticky cost and equity pledge by discussing the strategic choices of major shareholders to avoid risks during the equity pledge period.
Analysis on the Current Situation and Future Outlook of Coal Market in Indonesia
Authors: Li Ai
Published: December 2020

Based on the coal reserves, coal quality, geographical location and policy support of Indonesia, this paper discusses the prospect of coal resource development in Indonesia, and holds that Indonesia is rich in coal resources, has good coal quality index, is easy to opencast mining, and has a good coal export location, which can be the first choice for coal resource development in southeast Asia. At the same time, the advantages and problems of coal industry in Indonesia are analyzed, and it is suggested that joint ventures can be established with local companies to reduce investment risks caused by backward infrastructure and weak government supervision. Coal and electricity joint venture is an ideal investment and development model in the process of coal mine development in Indonesia.
The Economic Impact of Malaysia’s Institution on the Failure of the Wawasan 2020
Authors: Jianing XU
Published: December 2020

On the arrival of 2020, Malaysian President Mahathir officially announced the failure of Wawasan 2020, which is also called Vision 2020. This article discusses the cause of this failure from the perspective of institutional issues, namely political struggle, institutional corruption, supreme Malay policy. At the same time, this article puts forward the following opinions for the future economic development of Malaysia because of the above issues. The first thing to govern is the corruption of government officials and the corruption of the system. Secondly, the government should improve its unfair education system and reduce the drain of Chinese talents. Taking the Korean economy as an example, Malaysia can achieve a win-win situation with China through the Belt and Road Initiative.
A structure analysis of Chinese iron and steel industry based on Jingyou evaluation of performances of listed companies
Authors: Zhao Xinan , Kim Jongho , Pak Gyongsu
Published: December 2020

With the value ideology of modern strategic management, a new industrial structure analysis method was proposed based on the Jingyou theory rather than the traditional competitive mechanism in this paper, and then it was carried out to apply it to the performance data of the listed companies in the first quarter of 2017 in order to explain the structural feature of Chinese iron and steel industry. Such analysis results as the distributive feature of enterprise groups in industry, the main developing mode of industry, the identification of benchmarks and partners will be helpful to the detailed explanation of structural feature of industry under the objective law of development of things and contribute to solve some important problems in the modern corporate strategic management practice.
Fair Value Hierarchy and Audit Fees: An Empirical Analysis based on the Listed Banks in China
Authors: Qingyu Zhang
Published: December 2020

The key to the criticism of fair value lies in the lack of measurement in the active market quotation, while the fair value hierarchy hopes to make up for the reliability of fair value information by increasing disclosure. Using listed commercial bank data from 2007 through 2016, this paper documents that the assets and liabilities measured by fair value are significantly positively associated with audit fees. The positive association between audit fees and the fair value obtained via Level 2 or Level 3 inputs is greater than that Level 1.These results indicate that when the fair value needs to be estimated, the auditor needs to increase audit effort with resulting in higher audit fees. Moreover, the balance of assets and liabilities that fair-valued using Level 2 inputs is the largest and accounts for the highest proportion, which leads to more substantial changes in audit expenses. This result is consistent with the scale determinism of audit expenses. At the same time, due to the impact of professional judgment on the fair value hierarchy and the absence of corresponding supervision, the management has the motivation to use hierarchy for earnings management. The assets and liabilities that fair-valued using Level 2 inputs may represent the characteristics of fair value earnings management, audit risk is higher.
Analysis on the Change of India’s Billionaires and Its Reasons
Authors: Jin Shujun
Published: December 2020

Today the cultural communication between different countries and regions is intensified. Indian has won the attention of many people as a rising star in the market. In this article, an issue of intense debate, India’s billionaires, is the main theme. The knowledge source of this article involves the contents of authoritative books, treatises of other intellectuals, and the data on the Internet. According to the analysis, the conclusion can be drawn that India’s rich hold much fortune, which may be caused by its economic reform and crony capitalism. This article also hypotheses the future trend of the outlook: the number of Indian billionaires may still continue to increase. Nevertheless, under the help of Indian government and the improving institution, the increasing speed will be much slower and the trading behaviour of the upper class, which tends to be connected with the word corruption, may also be more legitimate.
Financial Performance Analysis of Backdoor Listed Companies
Authors: Yuhong Huang
Published: December 2020

IPO listing threshold requirements are high, many enterprises have chosen to backdoor listing due to the restrictions of objective factors. In order to study the impact of backdoor listing on corporate financial performance, this paper adopts the method of case analysis and takes SF Express, a typical representative of express delivery industry, as an example to analyze whether SF Express has improved its financial performance after backdoor listing by using financial indicators such as debt paying ability, operating ability, profitability and growth ability. The results show that the overall financial performance of SF Express has been improved due to the sufficient capital and the expansion of business scope. The innovation of this paper lies in the horizontal short-term comparison of financial data of SF Express which is backdoor listed and DEPPON Express which is IPO listed in express industry. The research shows that backdoor listing is more conducive to the improvement of the financial performance of enterprises in the short term, providing certain reference value for enterprises that want to go public by backdoor listing in the express industry in the future. However, when deciding to go public, different enterprises should choose suitable listing schemes according to their own financial characteristics and understand the risk and the strategic goal of the enterprise’s own development.
Analysis on Poverty Reduction Effects and Its’ Influencing Factors of Farmer Cooperatives in Contiguous and Extremely Poor Areas Based on the Investigation of Qinling-Bashan Mountainous Regions in Sichuan Province
Authors: Liu Guoqiang , Zhang Bizhong , Fu Xinhong , Zhang Ruixin
Published: December 2020

Based on the perspective of income increase of farmer cooperatives’ members, this paper uses the micro investigation data of 33 cooperatives and 394 members in Qinling-Bashan Mountainous Regions in Sichuan Province, to examine the poverty reduction effects of cooperatives and empirically analyze the factors influencing the poverty reduction effects of cooperatives by the orderly probit model. The results show that the income increase of most members is obvious, which is conducive to the in-depth development of local poverty alleviation. Besides, 9 variables play a significant role in promoting the income increase of members, which are health status, education level, number of labor, proportion of agricultural income, income satisfaction, cooperatives with county demonstration level, “Three Products and One Standard” certification, profit returned by stock/volume, member’s right to speak. Compared with Guangyuan, the income increase of members in Bazhong is more significant. However, the poor families and the distance from the market significantly inhibit the income increase of members, which means the cooperatives also face the challenges in poverty reduction. Finally, this paper puts forward policy suggestions for promoting the poverty reduction of cooperatives in Qinling-Bashan Mountainous Regions in Sichuan Province, such as cultivating and expanding cooperatives, strengthening the capacity of cooperatives to reduce poverty and improving the poverty reduction environment of cooperatives.
A Comparative Study of the Social Background, Functions and Types of the Ethnic Minority Property Rights System between the US, Canada and China
Authors: Jijian Gu
Published: December 2020

There are obvious differences of the property rights system between the United States, Canada and China’s ethnic minorities. They are reflected in differences of social background, the functions of property rights systems, and the types of property rights systems. From the perspective, the development of the property rights system is different from the general conclusions of the Demsetz.
Traffic demand Forecast of online car-hailing based on BP Neural Network
Authors: Jiang Junji
Published: December 2020

To accurately predict passengers’ demand for ride-hailing, increase transport capacity in some areas directionally, make it easier for passengers to book ride-hailing, and thus enhance passengers’ travel experience, based on BP neural network model, combined with 2015-Mak-2019 ride-hailing demand change data, and based on MATLAB platform, the demand trend of 20202024 is forecasted. The results show that the demand for shared cars and rides will increase rapidly. Demand for shared bikes and taxis is rising slowly.
Simulation Analysis of Opportunity Recognition Path of Small and Medium-Sized Manufacturing Enterprises in Dongguan —— Comparison between E-commerce and Traditional Relationship Network
Authors: Jiang Fu , Lei Fei , Zhang Ling
Published: December 2020

Small and medium-sized manufacturing enterprises in Dongguan use e-commerce and traditional relationship networks to build paths for market opportunity recognition. Taking the company’s monthly average total sales and total capacity as variables, this article employs particle swarm optimization (PSO) to simulate the paths of opportunity recognition in three different modes, namely the single e-commerce mode, the single traditional relationship network and their hybrid mode. The results reveal that: for the single ecommerce mode, the capacity utilization rate is very low; for the single traditional relationship network, changes in learning factor will not affect the choices of the enterprises; for the hybrid mode, the optimal solution of the three models is reached. But there is a substitution between the enterprise’s own learning factor and the group learning factor, which leads to deviation from the optimal solution
An Xgboost based system for financial fraud detection
Authors: LEI Shimin , XU Ke , HUANG YiZhe , SHA Xinye
Published: December 2020

Credit card fraud leads to billions of losses in online transaction. Many corporations like Alibaba, Amazon and Paypal invest billions of dollars to build a safe transaction system. There are some studies in this area having tried to use machine learning or data mining to solve these problems. This paper proposed our fraud detection system for e- commerce merchant. Unlike many other works, this system combines manual and automatic classifications. This paper can inspire researchers and engineers to design and deploy online transaction systems.
Predictive model of effective sustainable operation for sustainable development of enterprises
Authors: Wang Haitong , Cheng Ziyi , Li Hongyan
Published: December 2020

Business forecasting has a very important impact on the future development of listed companies. Especially in the current era of information, corporate financial information disclosure is more comprehensive, so a reasonable business forecasting model is particularly important in the market. For the study of business operation forecasting models, Chinese scholars have achieved relevant results. This article is mainly based on the existing models for innovation and development. By establishing two models, SR + CART and ANN + CART, and testing their prediction accuracy, it provides a more diverse and reasonable tool for business forecasting, which is beneficial to the efficient development of capital market. The results show that the ANN + CART model has higher prediction accuracy, and the overall prediction accuracy is 92%.
Analysis of problems and policy suggestions in the construction of business environment in China
Authors: CAO Yonghui , JIANG He
Published: December 2020

Building a good business environment is of positive significance for the healthy growth of enterprises and the high-quality development of China’s economy. China has achieved positive results in recent years, but there are still problems in some aspects, which has become an obstacle to the further development of China’s economy. Therefore, based on the actual situation of our state-owned business environment, this paper focuses on the core problems, analyzes the causes and puts forward relevant policy recommendations. This paper mainly analyzes the construction of government environment, business law environment and the internationalization of business environment, so as to provide reference and reference for the high quality of China’s economy.
Logical analysis of the impact of supply chain relationship quality on the growth performance of start-ups
Authors: JIANG He , CAO Yonghui
Published: December 2020

Due to the dilemma of “new entry defects” in the newly established enterprises, they are limited in developing new resources and cannot meet the increasingly fierce competition needs. Therefore, it is necessary to establish a stable strategic partnership by seeking external organizations, so as to obtain the necessary resources for the growth and development of the enterprise itself. Based on Penrose’s theory of enterprise growth, this paper analyzes the relationship between the quality of supply chain relationship and the growth performance of start-ups from three aspects, in order to reveal the internal logic that the quality of supply chain relationship affects the growth performance of start-ups.
Research on the Personal Privacy in the Health Big Data
Authors: JIA Cangcang , LIU Han
Published: December 2020

Data mining, data prediction and all-round digital monitoring of health big data make the dilemma of personal privacy control prominent. The weakening of the control of personal privacy by big data technology, the people’s data belief, the diversity of interests and the conflict of interests are the main causes of the problem of personal privacy in the context of the application of health big data. Therefore, in the application of health big data, the solution to the problem of personal privacy in the context of health big data application is to enhance the value transparency of big data technology, return and reshape humanism, and explore common values to reduce conflicts of interest.
A Review of Cultural Added Value Research Based on Knowledge Mapping Analysis
Authors: Yuan Ni , Lu Yang , Yudong Gao , Gongshan Cai
Published: December 2020

The enhancement of cultural added value to products is reflected in the level of personal cultural spiritual enjoyment, corporate cultural brand building and social cultural essence inheritance. Compared with ordinary products, the added value of products after incorporating cultural elements is the size of the product’s cultural added value. At the same time, different components of cultural added value can meet different cultural needs of consumers and reach emotional consensus with consumers to some extent. This complex diversity of value realization helps to lay a good foundation for developing cultural brands with Chinese characteristics and transmitting excellent traditional Chinese culture.
Research on Supply Chain Financial Risks and Preventive Measures in the Era of Big Data
Authors: Sun Weiting , Shen Puxue
Published: December 2020

The emergence of supply chain finance has reduced the financing costs of SMEs. Due to the development of a diversified supply chain financial subject platform, there is a lack of risk control in terms of theory and practice. Big data is generated in Internet applications and combined with information technology to form big data technology. It can provide financial institutions with large-scale data analysis methods and can effectively improve the efficiency and ability of financial institutions to serve supply chain members. However, big data has some problems, such as higher processing cost, lower authenticity, and difficulty in effectively protecting the privacy and security of users. There are many problems with this new development model. This article focuses on the risk problems faced by supply chain finance. It discusses the use of big data technology to effectively solve the supply chain financial risk problems, and gives some measures that can be effectively solved for how to effectively avoid these risk factors. By effectively solving the financial risk problem in the era of big data, it provides guarantee for the benign development of enterprises, and provides a certain reference for researchers engaged in related fields and workers in this field.
Research on Fiscal Sustainability Risk Evaluation Model Based on Large-Scale Regional Comprehensive Development PPP Project
Authors: Xianhao Li , Yue Wang , Lin Wang
Published: December 2020

With the development of urbanization in China, the traditional PPP mode is no longer suitable for the urbanization in China. Therefore, the regional comprehensive development PPP mode is gradually concerned by government and enterprises. In view of the above development trend, this paper establishes a model of fiscal sustainability risk for large-scale regional comprehensive development PPP project to realize efficient allocation of resources, value maximization, fiscal sustainability risk evaluation, so as to achieve fiscal sustainability.
Evaluation of Maritime Transport Support Mode for Islands and Reefs Based on DEA
Authors: Jiashuai Huang , Peng Dong , Yi Cai
Published: December 2020

On the basis of the analysis and summary of several maritime transport support modes for the material replenishment of islands and reef, a DEA model is established in this study to calculate the relative validity of the above-mentioned modes by solving the linear programming question. Consequently, the support modes can be sorted by the validity value. Finally, impact factors can be located and improvements can be made through eliminating the variables, leading to potential room for maritime transport support optimization.
Innovative Teaching Reform and Practice in Strategic Management of Enterprises Based on the Context of Enterprise Diversification
Authors: Cheng Ying , Liu Haibing
Published: December 2020

Strategic management of Enterprise is a comprehensive course, the teaching process integrated financial management, marketing human resources management and etc. Most of the enterprises will adopt diversified management as their strategic target to make profits by the impact of globalization. How to make students participate in learning process ,then use the management methods in real business management situation, try to identify four steps in strategic management by practicing in the enterprises, establish a strategic partnership platform for teachers-enterprises-students, make a effectively improvement though learning and teaching for all of the three in the end.
Multi-objective optimization model of waste tire recycling network
Authors: Wang Bin , Li HeHua
Published: December 2020

To achieve sustainable development, logistics enterprises need not only to reduce costs, but also to save energy for environmental protection and improve customer service level. The improvement of reverse logistics management level of waste tires is of great significance to improve the efficiency of the automobile industry. In this paper, multi-objective programming is adopted to establish the waste tire recycling network model. The decision variable is whether the network nodes are set or not, the traffic flow between nodes. Constraints include meeting customer demand, balance of flow in and out of logistics nodes, etc. The model is solved by ε- constraint. Taking the actual data of the enterprise as an example, the operation results show that the operation cost, carbon emission and customer transportation distance can get an consistence within a certain range. Waste tire logistics enterprises can realize the simultaneous improvement of profit, environmental protection and customer service level.
Das ZEPmax-Programm – effektive, leitliniengerechte multimodale Therapie von Adipositas und Folgeerkrankungen
Authors: Bischoff Gert , Bischoff Monika , Benend Veronika , Feiner Sebastian , Hohenester Simon , Rust Christian
Published: December 2020

Hintergrund Adipositas und die assoziierten Folgeerkrankungen führen nicht nur zu einer erhöhten Morbidität und Mortalität, sondern auch zu einer Reduktion der Lebensqualität. Obwohl ein multimodaler Therapieansatz die leitliniengerechte Therapie der Wahl für die meisten Patienten ist, fehlen in Deutschland flächendeckend geeignete Programme und die Ansprechraten unstrukturierter Interventionen sind unzureichend.

Material und Methodik Das ZEPmax-Programm ist ein konservatives, multimodales, 1-jähriges Therapieprogramm mit initialer Formuladiätphase für Erwachsene mit Adipositas. Die Patienten treffen sich jede Woche für 3,5 Stunden am Zentrum. Die Daten der ersten 136 konsekutiv eingeschlossenen Patienten wurden hier als Intention-to-treat-Analyse ausgewertet. Neben Gewicht und BMI wurden Faktoren des metabolischen Syndroms untersucht.

Ergebnisse Die Teilnehmer hatten einen durchschnittlichen BMI von 43,0 kg/m2. 11,8 % brachen das Programm im ersten Jahr ab. 87,5 % erreichten das primäre Therapieziel einer Gewichtsreduktion von > 10 % des Ausgangsgewichts bei einem durchschnittlichen Gewichtsverlust von 24,7 kg (19 % des Ausgangsgewichts). 72 % der Diabetespatienten (n = 18) erreichten eine vollständige Remission, d. h. einen normwertigen HbA1c ohne spezifische Diabetesmedikation. Der systolische Blutdruck der Hypertoniepatienten (n = 53) sank im Mittel um 22 mmHg. Das Gesamtcholesterin der Patienten mit Hyperlipidämie (n = 66) konnte um 23 mg/dl und das LDL-Cholesterin um 17 mg/dl gesenkt werden.

Schlussfolgerung Die vorliegende Arbeit zeigt, dass mit Hilfe des strukturierten, formuladiätbasierten, multimodalen Adipositas-Therapieprogramms ZEPmax ein nachhaltiger Gewichtsverlust mit hohen Ansprechraten erreicht werden kann. Durch erfolgreiche Therapie der Adipositas konnten die assoziierten Folgeerkrankungen Diabetes mellitus Typ 2, arterielle Hypertonie und Hyperlipidämie mit hohen Remissionsquoten behandelt werden. Die vorliegende Arbeit belegt den Stellenwert einer professionell durchgeführten konservativen Adipositastherapie in Deutschland.
Berufliche Rehabilitation nach posttraumatischer linksseitiger Unterarmamputation
Authors: Greitemann Bernhard , Meinecke-Allekotte Britta
Published: December 2020

Der vorliegende Bericht schildert beispielhaft
die Möglichkeit einer beruflichen Rehabilitation
selbst bei einem Extremitätenverlust
an der oberen Extremität, auch bei
beruflich beanspruchender Tätigkeit. Dies
erfordert eine interdisziplinäre, längerdauernde
Rehabilitation in einem Team, das
sich mit der Versorgung von Extremitätenverlusten
beschäftigt. Erforderlich ist des
Weiteren eine hohe Motivation des oder
der Betroffenen.
Early Life Care
Authors: Wittmann Stefanie , Müller-Gorman Irmi
Published: December 2020

Early Life Care ist ein international anerkanntes interdisziplinäres und integratives Konzept der Gesundheitsförderung und -versorgung. Dabei geht es um Beratung, Begleitung und Versorgung ab dem Lebensbeginn. Ziel ist die Schaffung möglichst optimaler Bedingungen in der frühen Kindheit, rund um Kinderwunsch, Schwangerschaft, Geburt und erstes Lebensjahr.
Mechanism of lncRNA H19 in Regulating Pulmonary Injury in Hyperoxia-Induced Bronchopulmonary Dysplasia Newborn Mice
Authors: Zhang Lina , Wang Ping , Shen Yanhong , Huang Tao , Hu Xiaoyun , Yu Wei
Published: December 2020

Objective Bronchopulmonary dysplasia (BPD) is a pulmonary injury related to inflammation and is a major cause of premature infant death. Long noncoding RNAs (lncRNAs) are important regulators in pulmonary injury and inflammation. We investigated the molecular mechanism of lncRNA H19 in pulmonary injury and inflammation in hyperoxia (Hyp)-induced BPD mice.

Study Design The BPD newborn mouse model was established and intervened with H19 to evaluate the pathologic conditions and radial alveolar count (RAC) in lung tissues of mice in the room air (RA) and Hyp group on the 4th, 7th, and 14th days after birth. The levels of BPD-related biomarkers vascular endothelial growth factor (VEGF), transforming growth factor β1 (TGF-β1), and surfactant protein C (SPC) in lung tissues were detected on the 14th day after birth. The expression of and relationships among H19 and miR-17, miR-17, and STAT3 were detected and verified. Levels of interleukin (IL)-6, IL-1β, p-STAT3, and STAT3 levels in mouse lung tissues were detected on the 14th day after birth.

Results Hyp-induced mice showed increased alveolar diameter, septum, and hyperemia and inflammatory cell infiltration, upregulated H19, decreased overall number and significantly reduced RAC on the 7th and 14th days after birth, which were reversed in the si-H19-treated mice. VEGF was upregulated and TGF-β1 and SPC was decreased in si-H19-treated mice. Moreover, H19 competitively bound to miR-17 to upregulate STAT3. IL-6 and IL-1β expressions and p-STAT3 and STAT3 levels were downregulated after inhibition of H19.

Conclusion Downregulated lncRNA H19 relieved pulmonary injury via targeting miR-17 to downregulate STAT3 and reduced inflammatory response caused by p-STAT3 in BPD newborn mice.

Key Points
Medical hybridity and beyond: professional transitions in Italian outpatient settings
Authors: Sofritti Federico
Published: December 2020

The marketization of public healthcare has brought about organizational transformations, affecting health professionals' ways of working in hospitals and outpatient organizations. As a result of the reforms in the 1990s, the principle of business-like healthcare has been introduced in the Italian health system. This paper presents the main findings of a study of specialist doctors working in two local health organizations in the Tuscany region. Drawing on semi-structured interviews with specialist doctors working in an outpatient setting, the article examines the manifold reactions to changes of the medical profession within outpatient settings. In particular, the combination of professional and organizational dimensions has been taken into consideration. The results show that a change is involving outpatient specialist doctors' identity: organizational change affects several dimensions of the medical professional ethos. The change has been understood by categorizing three major types of approaches to medical professionalism, which are aimed to understand the complexity of the domain and to summarize professionals' reactions: the first is linked to a traditional model of professionalism; the second accepts partially business-like organizational issues, while trying to create individual spaces of autonomy in daily tasks; the third co-opts new organizational issues, which become part of the medical professional ethos.
Small Towns and Land Reform in Zimbabwe
Authors: Scoones Ian , Murimbarimba Felix
Published: December 2020

Zimbabwe’s land reform from 2000 radically transformed the agrarian structure, and with this small towns in rural areas. This article explores three such towns—Mvurwi, Chatsworth and Maphisa—examining changes in population, housing, transport and business activity between 2000 and 2020. Case studies highlight the importance of networks and social relationships between rural and urban areas, linked to new patterns of migration and a massive growth in the informal economy. Despite the lack of state investment in basic infrastructure, the economies of these small towns have grown significantly, with a major shift in agrarian relations generating new economic activity and employment. This suggests the potential of a territorial focus for local economic development following land reform, encompassing both urban and rural areas.
A (3 + 1)-dimensional nonlinear extended Zakharov–Kuznetsov dynamical equation: Bifurcation and traveling wave solutions
Authors: Arab M. M.
Published: December 2020

This paper studies the (3 + 1) extended Zakharov–Kuznetsov (EZK) dynamical equation that is utilized to describe nonlinear three-dimensional dust-ion-acoustic solitary waves in a magnetized two-ion-temperature dusty plasma. The bifurcation theory for planar dynamical systems is applied to the EZK equation. For a given restriction on the parameters, some new traveling wave solutions are characterized in terms of Jacobi-elliptic functions. These solutions are clarified in a graphical way. Physically, these wave solutions represent the related electric potential. Based on Maxwell equations, we calculate the corresponding electric magnetic fields, and we clarify them graphically.
An information structure scenario for V2 loss in Medieval French
Authors: Larrivée Pierre
Published: December 2020

This paper discusses word order change in Medieval French. Verb-second (V2) configurations are generally understood as having an initial XP and the verb in the left periphery. How has this configuration been lost in French? Under an Information Structure scenario, the XP is in initial position because of its characterized (discourse-old) informational value, which motivates the left-peripheral position of the verb. The decline of the characterized informational value of the XP thus accounts for the gradual loss of V2. The informational behaviour of XPs was examined in unambiguous V2 configurations with an overt post-verbal subject in Medieval French. This detailed quantitative study of a calibrated corpus shows that XPs with a characterized informational value were predominant with productive V2 configurations, that they gradually declined as productive V2 was lost, and that they increasingly failed to attract the verb to the left periphery. These observations can be accounted for if V2 in Medieval French was driven by informational values and if it disappeared along with the informational cues provided by the XPs.
Validation of Newton’s second law using Arduino: STEM teaching material
Authors: Çoban Atakan , Erol Mustafa
Published: December 2020

The present work offers an experimental technique specially designed and employed to comprehend and teach the Newton’s second law and to overcome certain instructional difficulties. The apparatus is mainly comprised of two specifically designed toy cars, two force sensors, one distance sensor, a pulley, two pieces of gut, an Arduino microprocessor and an ordinary computer. Newton’s second law is experimentally validated by measuring, using the Arduino system, the accelerations from the distance–time graphs and by directly measuring the tension forces. The experimental results are also compared with theoretical calculations, indicating a reasonably good agreement. The designed apparatus can be employed as a Science Technology Engineering Mathematics teaching material within physics laboratories, to achieve enhanced understanding of Newton’s second law and dynamics.
Switchable dual-wavelength erbium-doped fiber laser based on the broadband filtering performance of tapered long period fiber gratings
Authors: Nuñez-Gomez R E , Anzueto-Sánchez G , Camas-Anzueto J L , Martínez-Rios A , Basurto-Pensado M A , Castrellon-Uribe J
Published: December 2020

In this paper, a switchable, dual-wavelength erbium-doped fiber laser, based on the broadband filtering performance of a tapered long-period fiber grating, is experimentally demonstrated. The lasing emission can be built up in sets of dual-wavelengths in the entire C-band, with variable and controllable separation between laser lines from 6.75 nm to 35 nm when the optical fiber filter structure is gradually bent.
Turbulent pulsations in the axisymmetrical submerged jet
Authors: Lemanov V V , Terekhov V I , Sharov K A , Shumeiko A A
Published: December 2020

Today, the turbulent characteristics of laminar jets remain almost unexplored, although all real flows have a pulsating component, which in technological processes can have a significant effect on the processes of mixing, heat and mass transfer. The turbulent characteristics of a submerged laminar air jet flowing out of a tube with a diameter of 3.2 mm and length of more than 100 diameters were experimentally investigated at Reynolds number of 436. The measurements were carried out using a hot-wire anemometer. The ranges of operating parameters at which the laminar, transitional and turbulent flows occur in the jet source have been determined. Based on the data obtained, the regime for the study was selected. For the selected regime, the profiles of average velocities and pulsations in cross-sections along the jet flow were measured and distributions of turbulent characteristics along the jet flow on the axis and in the mixing layers were constructed.
Investigation of the cascade mechanism of energy exchange in swirling gas flows based on the effect of secondary swirling
Authors: Volov V T , Lyaskin A S
Published: December 2020

The article presents the results of studies of the secondary swirling effect in supersonic rotating gas and plasma flows. It is shown that the secondary twist of the jets of gas flowing from the nozzle apparatus generates a cascade structure of vortices that separate energy in the field of azimuthal and radial pressure gradients. As shown by the calculations, the effect of energy separation is more significant the higher the level of secondary twisting of the nozzle jets, which, in turn, is determined by the level of energy dissipation. Experimental confirmations of the revealed cascade mechanism of energy separation in supersonic swirling gas flows are discussed.
Rivulet structures formation, rupture and heat transfer in the falling liquid films
Authors: Chinnov E A
Published: December 2020

The evolution of three-dimensional waves into thermocapillary-wave structures, rivulets deflection, heat transfer enhancement and rupture vertically falling water film at heating were studied. Characteristics of the film flow were determined experimentally using simultaneous measurements of thickness and temperature fields on the falling heated liquid film surface (LIF and IR scanner). The amplitudes and velocities of waves, amplitudes of rivulet deflection, temperature fluctuations on the film surface, frequency spectra and pulsation energies were determined. Several different types of instability were registered on the surface of the heated fluid film: 3D hydrodynamic and thermocapillary A, B and C instabilities. The thermocapillary structures of type A arise in the residual layer behind the front of the wave, leading to an increase in the amplitude of the waves and rivulets deflection amplitudes. It is shown that the heat flux of rupture increases and intensity of heat transfer enhances due to an increase in the surface waves and rivulet deflection amplitudes.
Determination of Afzelin and Astragalin fromLespedeza cuneataon Aldose Reductase Inhibition
Authors: Lee Dong Gu , Lee Ju Sung , Quilantang Norman G , Jacinto Sonia D , Lee Sanghyun
Published: December 2020

The bioactive chemicals in L. cuneata were investigated by repeated column chromatography and their effect on aldose reductase (AR), obtained from rat lenses, was examined. Results showed that the ethyl acetate and n-butanol fractions of L. cuneata exhibited potential inhibitory effect against AR with IC50 values of 0.57 and 0.49 μg/mL, respectively. Phytochemical analysis of these two fractions resulted in the isolation of five flavonoids namely, acacetin (1), afzelin (2), astragalin (3), kaempferol (4) and scutellarein 7-O-glucoside (5). The AR inhibitory effect of compounds 1-5 was explored; compounds 2, 3 and 5 showed potential AR-inhibitory effects with IC50 values of 2.20, 1.91 and 12.87 μM, respectively. Quantitative analysis of afzelin (2) and astragalin (3) in L. cuneata by high performance liquid chromatography with ultraviolet detection revealed its content to be 0.722–11.828 and 2.054–7.006 mg/g, respectively. Overall, this study showed that L. cuneata is rich in flavonoids with promising AR-inhibitory activities, which can be utilized for the development of natural therapies for treating and managing diabetic complications.
Assessment of fecal steroid and thyroid hormone metabolites in eastern North Pacific gray whales
Authors: Lemos Leila S , Olsen Amy , Smith Angela , Chandler Todd E , Larson Shawn , Hunt Kathleen , Torres Leigh G
Published: December 2020

Baleen whale fecal samples have high potential for endocrine monitoring, which can be used as a non-invasive tool to identify the physiological response to disturbance events and describe population health and vital rates. In this study, we used commercial enzyme-linked immunosorbent assays to validate and quantify fecal steroid (progestins, androgens and glucocorticoids) and thyroid hormone metabolite concentrations in eastern North Pacific gray whales (Eschrichtius robustus) along the Oregon coast, USA, from May to October of 2016–2018. Higher mean progestin metabolite concentrations were observed in postweaning females, followed by pregnant females. Mean androgen, glucocorticoid and thyroid metabolites were higher in mature males. Progestin, glucocorticoids and thyroid fecal metabolites varied significantly by year, with positive correlations between progestin and androgen, and between glucocorticoid and thyroid metabolites. We also present two case studies of a documented injured whale and a mature male displaying reproductive competitive behavior, which provide reference points for physiologically stressed individuals and adult breeding males, respectively. Our methods and findings advance the knowledge of baleen whale physiology, can help guide future research on whale physiology and can inform population management and conservation efforts regarding minimizing the impact of anthropogenic stressors on whales.
Endoglucanase activity of cellulolytic bacteria from lake sediments and its application in hydrophyte degradation
Authors: Zhang Hongpei , Li Qianzheng , Zhao Yuqing , Zhang Mingzhen , Xu Dong , Wu Zhenbin , Zhou Qiaohong
Published: December 2020

Hydrophytes are plants that grow in or on water. Their overgrowth adversely affects the ecosystem because of crowding out other aquatic organisms and polluting the environment with plant residue. In principle, cellulolytic bacteria can be used to degrade hydrophyte biomass. We here isolated and characterized four cellulolytic bacterial strains from Lake Donghu sediments (Wuhan, China) that are rich in organic matter and plant residues. The isolates (WDHS-01 to 04) represent Bacillus, Micromonospora and Streptomyces genera. The bacteria exhibited pronounced endoglucanase activities (from 0.022 to 0.064 U mL–1). They did not extensively degrade the emerged plant Canna indica L. However, in an Hydrilla verticillata (submerged plant) degradation medium, strain WDHS-02 exhibited a high degradation rate (54.91%), endoglucanase activity of 0.35 U mL–1 and the conversion rate of cellulose to reducing sugars of 7.15%. Correlation analysis revealed that bacterial endoglucanase activity was significantly correlated with the degradation rate, and acid detergent lignin, ash and cellulose content of the residual H. verticillata powder. In conclusion, the identified bacteria efficiently decomposed submerged plants without the need for acid–base pretreatment. They expand the set of known cellulolytic bacteria and can be used for natural degradation of submerged plants.
Malyl-CoA lyase provides glycine/glyoxylate synthesis in type I methanotrophs
Authors: But S Y , Egorova S V , Khmelenina V N , Mustakhimov I I
Published: December 2020

The biochemical routes for assimilation of one-carbon compounds in bacteria require many clarifications. In this study, the role of malyl-CoA lyase in the metabolism of the aerobic type I methanotroph Methylotuvimicrobium alcaliphilum 20Z has been investigated by gene inactivation and biochemical studies. The functionality of the enzyme has been confirmed by heterologous expression in Escherichia coli. The mutant strain lacking Mcl activity demonstrated the phenotype of glycine auxotrophy. The genes encoding malyl-CoA lyase are present in the genomes of all methanotrophs, except for representatives of the phylum Verrucomicrobium. We suppose that malyl-CoA lyase is the enzyme that provides glyoxylate and glycine synthesis in the type I methanotrophs supporting carbon assimilation via the serine cycle in addition to the major ribulose monophosphate cycle.
A Strategic Forest Management Model for Optimizing Timber Yield and Carbon Sequestration
Authors: Carle Marc-André , D’Amours Sophie , Azouzi Riadh , Rönnqvist Mikael
Published: December 2020

Strategic forest management planning models designed to maintain existing carbon stocks and maximize capacity for future sequestration can help identify underused opportunities to increase carbon stocks without diminishing other forest products. This study proposed a carbon stock unit that allows summing up the stocks in the different forest pools even if the decomposition far exceeds the planning horizon. This unit is used to integrate the methods and algorithms from the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3) model into a wood supply model. The resulting model could be used to predict changes in carbon stocks, transfers between carbon pools, and greenhouse gas emissions that would result from every forest management activity. We tailored this model to meet different strategies: maximizing carbon storage in the forest, maximizing high-sustained timber yield, and achieving the dual objectives of yield and carbon storage. A range of management scenarios were simulated using the data of a 485,000 hectares mixed-wood forest in Quebec, Canada. Our results demonstrate that, with the reduction in the harvest rates, the increase in the ecosystem carbon storage is insufficient to offset the carbon losses associated with the increase in the harvest rates.
Association of Complicated Diverticulitis With Development of De Novo Inflammatory Bowel Disease
Authors: ur Rahman Asad , Hussain Ishtiaq , Hasan Badar , ur Rashid Mamoon , Tandon Kanwarpreet Singh , Castro Fernando
Published: December 2020

Background

There has been a historic similarity in the epidemiology and pathophysiology of diverticular disease and inflammatory bowel disease (IBD). Because there are limited to no data on the role of diverticulitis as a potential risk factor for de novo IBD, we aimed to evaluate the role of diverticulitis and complicated diverticulitis as a potential predictor of IBD.

Methods

We performed a retrospective, single-center study including patients older than age 18 years who were diagnosed with diverticulitis from January 2012 until December 2018 without a prior diagnosis of IBD. These patients were then evaluated for development of IBD. Univariate and multivariate analyses were conducted to compare the characteristics and outcomes between patients who did or did not develop IBD.

Results

A total of 2770 patients were diagnosed with diverticulitis from 2012 until 2018. Of these patients, 17 were diagnosed with IBD, resulting in an incidence rate of 0.23% per patient-year. The incidence rate among patients who required surgery for diverticulitis was 0.44% per patient-year, and patients with complicated diverticulitis had an incidence rate of 0.91% per patient-year. Univariate analysis showed that the need for surgery related to diverticulitis (hazard ratio [HR], 6.27; P = 0.003) and complicated diverticulitis was associated with the development of IBD (HR, 14.71; P < 0.001). Multivariate analysis showed that complicated diverticulitis was the sole factor associated with IBD (HR, 10.34; P < 0.001).

Conclusions

Patients with diverticulitis are at a higher risk of developing de novo IBD. This risk is highest in patients with complicated diverticulitis.