Construction of a Shuttle Vector for Heterologous Expression of a Novel Fungal a-Amylase Gene in Aspergillus oryzae

( Yanchen Yin ),( Youzhi Mao ),( Xiaolie Yin ),( Bei Gao ),( Dongzhi Wei ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.7

The filamentous fungus Aspergillus oryzae is a well-known expression host used to expresshomologous and heterologous proteins in a number of industrial applications. To facilitate higher yields of proteins of interest, we constructed the pAsOP vector to express heterologous proteins in A. oryzae. pAsOP carries a selectable marker, pyrG, derived from Aspergillus nidulans, and a strong promoter and a terminator of the amyB gene derived from A. oryzae. pAsOP transformed A. oryzae efficiently via the PEG-CaCl2-mediated transformation method.As proof of concept, green fluorescent protein (GFP) was successfully expressed in A. oryzae transformed by pAsOP-GFP. Additionally, we identified a novel fungal α-amylase (PcAmy) gene from Penicillium sp. and cloned the gene into the vector. After transformation by pAsOPPcAmy, the α-amylase PcAmy from Penicillium sp. was successfully expressed in a heterologous host system for the first time. The α-amylase activity in the A. oryzae transformant was increased by 62.3% compared with the untransformed A. oryzae control. ThePcAmy protein produced in the system had an optimum pH of 5.0 and optimum temperature of 30oC. As a cold-adapted enzyme, PcAmy shows potential value in industrial applications because of its high catalytic activity at low temperature. Furthermore, the expression vector reported in this study provides promising utility for further scientific research and biotechnological applications.

재한 중국인 유학생의 문화적응 스트레스가 심리적 안녕감과 학업적응에 미치는 영향

Xiao XiaoLi(XiaoLi Xiao),안도희(Doehee Ahn) 중앙대학교 한국교육문제연구소 2016 한국교육문제연구 Vol.34 No.3

본 연구에서는 재한 중국인 유학생들을 대상으로 문화적응 스트레스가 심리적 안녕감과 학업적응에 미치는 직·간접효과와 이들 변인들에서 중국인 유학생의 교우관계 유형에 따른 두 집단(한국인 친구 다수집단, 중국인 친구 다수 집단) 간 차이가 있는지에 대해 탐색하고자 하였다. 본 연구의 최종분석 대상은 한국에 소재한 17개 대학교에서 유학 중인 중국인 유학생 총 363명이었다. 본 연구 결과, 문화 적응 스트레스는 심리적 안녕감과 학업적응에 직·간접적으로 부정적인 영향을 미치는 것으로 나타났 다. 또한, 한국인 친구 다수 집단은 중국인 친구 다수 집단에 비해 문화적응 스트레스가 낮으며 심리 적 안녕감 및 학업적응이 높은 것으로 나타났다. 이에, 재한 중국인 유학생의 보다 나은 학업적응을 위해 이들의 심리적 안녕감을 증진시키고, 이들의 문화적응 스트레스를 완화시킬 필요가 있다. 또한, 이들의 심리적 안녕감 증진을 위해 문화적응 스트레스 완화방안을 강구할 필요가 있는 것으로 판단된다. This study examined the direct and indirect influences of Chinese international students’ acculturative stress on psychological well-being and academic adjustment in Korea. The final sample consisted of 363 Chinese international students surveyed from 17 universities in Korea. Findings showed that Chinese international students with more Korean friends had less acculturative stress (i.e., perceived discrimination, homesickness, perceived hate, guilt, and miscellaneous), psychological well-being (i.e, self-acceptance, positive relations with others, autonomy, environment mastery, purpose in life, personal growth) and higher academic adjustment (i.e, motivation, application, performance and academic environment) than those with more Chinese friends. Moreover, it was found that acculturative stress had a direct negative effect on both psychological well-being and academic adjustment. Also, acculturative stress had a indirect negative effect on academic adjustment. Results are discussed in relation to theoretical implications in school settings.

Scheduling with Heterogeneous QoS Provisioning for Indoor Visible-light Communication

Xiaoli Dong,Xuefen Chi,Hongliang Sun,Yuhong Zhu 한국광학회 2018 Current Optics and Photonics Vol.2 No.1

Visible-light communication (VLC) combined with advanced illumination can be expected to become an integral part of next-generation communication networks. One of the major concerns in VLC implementation is developing resource-allocation schemes in a multi-user scenario. However, the scheduling for heterogeneous quality of service (QoS) traffic has not been studied so far, for the indoor VLC downlink system. In this paper, we creatively introduce effective-bandwidth and effective-capacity theory into the multi-user scheduling (MUS) problem, to guarantee the user’s statistical delay QoS. We also take account of the aggregate interference (AI) in the indoor VLC downlink system, and analyze its impact on the user-centric MUS problem for the first time. Simulations show that the AI has a nonnegligible influence on the scheduling result, and that the proposed scheduling scheme could guarantee the user’s QoS requirement under the premise of ensuring sum capacity.

$L^2$ harmonic $1$-forms on submanifolds with weighted Poincar\'{e} inequality

Xiaoli Chao,Yusha Lv 대한수학회 2016 대한수학회지 Vol.53 No.3

In the present note, we deal with $L^2$ harmonic $1$-forms on complete submanifolds with weighted Poincar\'{e} inequality. By supposing submanifold is stable or has sufficiently small total curvature, we establish two vanishing theorems for $L^2$ harmonic $1$-forms, which are some extension of the results of Kim and Yun, Sang and Thanh, Cavalcante Mirandola and Vit\'{o}rio.

The Effect of Leader–Member Exchange on Task Performance

Xiaoli CHE,A,FAKHRORAZI,Swarmilah HARIANI,Loke WEI-KIT,Lim FOO-WAH 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.6

This study examines the effect of leader–member exchange (LMX) on knowledge workers (k-workers)’s task performance and the mediating effect of affective commitment on the relationship between LMX and task performance; the analysis of such relationship, informed by the Social Exchange Theory, will make a theoretical contribution to k-workers’ working behavior in China. The technique of data collection in this study involved 280 k-workers respondents from China to whom a self-administered questionnaire was distributed. Data were analyzed using Partial Least Square (PLS) with Structural Equation Modeling (SEM) tools. The results show that LMX has a positive relationship with affective commitment and task performance. The result also confirmed the mediating effect of affective commitment on the relationship between LMX and task performance. This research provides some guidance to manage, motivate, and inspire the k-workers, and finally promote the organizational performance. The main point of the results is that it is essential for managers to keep a good and harmonious relationship with their subordinates. When the level of LMX between leaders and k-workers is high, they are more willing to stay in their organization, which is helpful to promote their task performance and brings benefit to the organizational performance.

The Intelligent Task Scheduling Algorithm in Cloud Computing with Multistage Optimization

XiaoLi He,Yu Song,Ralf Volker Binsack 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.4

There’re huge numbers of users and various tasks need to be handled in the cloud computing environment, the high effective task scheduling algorithm is one of the crucial problems that the cloud computing need to solve. Aiming to the model structure of cloud computing, in this article it introduces the Particle Swarm Optimization algorithm (PSO) and Ant Colony Optimization algorithm (ACO) to combine with optimized task scheduling algorithm. First it takes the particle swarm optimization algorithm to generate the initial scheduling results, and introduces the random inertia weight to improve the scheduling ability of the algorithm, then to take the generated results of improved particle swarm optimization algorithm as the initial pheromones of the ant colony algorithm to find out the optimal scheduling scheme, and use the elitist strategy and crossover operator in the genetic algorithm to improve the ant colony algorithm, among the algorithms to use multistage optimization algorithm to improve the operating efficiency. The experimental results show that under the same conditions, the total task completion time of improved algorithm has been reduced and its performance advantage are getting more obvious with the increased task measures.

A Novel Method to Calculate the Carbides Fraction from Dilatometric Measurements During Cooling in Hot‑Work Tool Steel

Xiaoli Zhao,Chuanwei Li,Lizhan Han,Jianfeng Gu 대한금속·재료학회 2018 METALS AND MATERIALS International Vol.24 No.6

Dilatometry is a useful technique to obtain experimental data concerning transformation. In this paper, a dilation conversionalmodel was established to calculate carbides fraction in AISI H13 hot-work tool steel based on the measured length changes. After carbides precipitation, the alloy contents in the matrix changed. In the usual models, the content of carbon atoms afterprecipitation is considered as the only element that affects the lattice constant and the content of the alloy elements suchas Cr, Mo, Mn, V are often ignored. In the model introduced in this paper, the alloying elements (Cr, Mo, Mn, V) changescaused by carbides precipitation are incorporated. The carbides were identified using scanning electron microscope andtransmission electron microscope. The relationship between lattice constant of carbides and temperature are measured byhigh-temperature X-ray diffraction. The results indicate that the carbides observed in all specimens cooled at different ratesare V-rich MC and Cr-rich M23C6,and most of them are V-rich MC, only very few are Cr-rich M23C6. The model includingthe effects of substitutional alloying elements shows a good improvement on carbides fraction predictions. In addition, lowercooling rate advances the carbides precipitation for AISI H13 specimens. The results between experiments and mathematicalmodel agree well.

Selection of High Laccase-Producing Coriolopsis gallica Strain T906: Mutation Breeding, Strain Characterization, and Features of the Extracellular Laccases

( Xiaoli Xu ),( Lei Feng ),( Zhenya Han ),( Sishi Luo ),( Ai`min Wu ),( Jun Xie ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.9

Commercial application of laccase is often hampered by insufficient enzyme stocks, with very low yields obtained from natural sources. This study aimed to improve laccase production by mutation of a Coriolopsis gallica strain and to determine the biological properties of the mutant. The high-yield laccase strain C. gallica TCK was treated with N-methyl-N-nitro Nnitrosoguanidine and ultraviolet light. Among the mutants isolated, T906 was found to be a high-production strain of laccases. The mutant strain T906 was stabilized via dozens of passages, and the selected ones were further processed for optimization of metallic ion, inducers, and nutritional requirements, which resulted in the optimized liquid fermentation medium MF9. The incubation temperature and pH were optimized to be 30°C and 4.5, respectively. The mutant strain T906 showed 3-times higher laccase activity than the original strain TCK under optimized conditions, and the maximum laccase production (303 U/ml) was accomplished after 13 days. The extracellular laccase isoenzyme 1 was purified and characterized from the two strains, respectively, and their cDNA sequence was determined. Of note, the laccase isoenzyme 1 transcription levels were overtly increased in T906 mycelia compared with values obtained for strain TCK. These findings provide a basis for C. gallica modification for the production of high laccase amounts.

Equivalent Transfer Function based Multi-loop PI Control for High Dimensional Multivariable Systems

Xiaoli Luan,Qiang Chen,Fei Liu 제어·로봇·시스템학회 2015 International Journal of Control, Automation, and Vol.13 No.2

A new equivalent transfer function (ETF) parameterization algorithm to incorporate the loop interaction effect into the design of multi-loop PI controllers for high dimensional multivariable processes is presented in this paper. The design scheme consists of two stages. In the first, by exploiting the relationship between the equivalent closed-loop transfer function and the inverse of open-loop transfer function, the analytical expression of ETF is derived. In the second stage, based on the ETF, controller parameters for each loop are determined by utilizing the existing PI tuning rules and the simple internal model control method. The proposed ETF parameterization algorithm is more accurate and reasonable compared to the conventional ETF model approximation methods. Furthermore, the advantage of the multi-loop PI controller designed by the proposed ETF is more significant when applied to higher dimensional processes with complicated interaction modes. Several typical industrial process examples show the well-balanced and robust response with the minimum integral absolute error.

A Method of Image Identification in Instrumentation

Xiaoli Wang,Shilin Wang,Baochen Jiang 한국정보처리학회 2018 Journal of information processing systems Vol.14 No.3

Smart city is currently the main direction of development. The automatic management of instrumentation isone task of the smart city. Because there are a lot of old instrumentation in the city that cannot be replacedpromptly, how to makes low-cost transformation with Internet of Thing (IoT) becomes a problem. This articlegives a low-cost method that can identify code wheel instrument information. This method can effectivelyidentify the information of image as the digital information. Because this method does not require a lot ofmemory or complicated calculation, it can be deployed on a cheap microcontroller unit (MCU) with low readonlymemory (ROM). At the end of this article, test result is given. Using this method to modify the oldinstrumentation can achieve the automatic management of instrumentation and can help build a smart city.