Controlling Dynamic Formations of Mobile Agents Governed by Euler-Lagrange Dynamics

Liangming Chen,Qingkai Yang,Chuanjiang Li,Guangfu Ma 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.5

This paper studies the problem of controlling dynamic formations of mobile agents governed by EulerLagrange dynamics. Here a formation is said to be dynamic if as time evolves, the desired formation undergoes translation, scaling and rotation. First, a constant-gain formation control algorithm is designed such that all agents can converge to the desired dynamic formation, in which the graphic information is needed for the selection of constant gains. Then, another fully distributed formation control algorithm is further proposed by employing variablegain control techniques, which enables each agent to be independent of the knowledge of the overall interaction graph needed otherwise in the control gain. Instead of moving with a desired translational velocity, a centroidtracking formation control algorithm is also proposed such that the centroid of the formation tracks a desired trajectory. The parametric uncertainties are taken into consideration in the proposed formation control algorithms. Finally, simulation examples are provided to validate the effectiveness of the proposed control algorithms.

Risk Factors for Poor Outcomes Following Minimally Invasive Discectomy: A Post Hoc Subgroup Analysis of 2-Year Follow-up Prospective Data

Zihao Chen,Lei He,Lijun Huang,Zhongyu Liu,Jianwen Dong,Bin Liu,Ruiqiang Chen,Liangming Zhang,Peigen Xie,Limin Rong 대한척추신경외과학회 2022 Neurospine Vol.19 No.1

Objective: A post hoc subgroup analysis of prospectively collected data from a randomized controlled trial was conducted to identify risk factors related to poor outcomes in patients who underwent minimally invasive discectomy. Methods: Patients were divided into satisfied and dissatisfied subgroups based on Oswestry Disability Index (ODI), visual analogue scale (VAS) back pain score (VAS-back) and leg pain score (VAS-leg) at short-term and midterm follow-up according to the patient acceptable symptom state threshold. Demographic characteristics, radiographic parameters, and clinical outcomes between the satisfied and dissatisfied subgroups were compared using univariate and multivariate analysis. Results: A total of 222 patients (92.1%) completed 2-year follow-up, and the postoperative ODI, VAS-back, and VAS-leg were significantly improved after surgery as compared to preoperatively. Multivariate analysis indicated older age (p = 0.026), lateral recess stenosis (p = 0.046), and lower baseline ODI (p = 0.027) were related to poor short-term functional improvement. Higher baseline VAS-back (p = 0.048) was associated with poor short-term relief of back pain, while absence of decreased sensation (p = 0.019) and far-lateral disc herniation (p = 0.004) were associated with poorer short-term relief of leg pain. Lumbar facet joint osteoarthritis was identified as a risk factor for poor functional improvement (p = 0.003) and relief of back pain (p = 0.031). Disc protrusion (p = 0.036) predicted poorer relief of back pain at midterm follow-up. Conclusion: In this study, several factors were identified to be predictive of poor surgical outcomes following minimally invasive discectomy. (ClinicalTrials.gov number: NCT01997086).

Genetic dissection of leaf-related traits using 156 chromosomal segment substitution lines

Xi Liu,Linglong Liu,Yinhui Xiao,Shijia Liu,Yunlu Tian,Liangming Chen,Zhiquan Wang,Ling Jiang,Zhigang Zhao,Jianmin Wan 한국식물학회 2015 Journal of Plant Biology Vol.58 No.6

A two-line super-hybrid rice (Oryza sativa L.) variety [Liangyoupei9 (LYP9)] demonstrated superiority over its both parents, viz. elite inbred lines 93-11 and Pei-ai64S (PA64S), as well as other conventional hybrids, and had long been exploited in China. However, the genetic basis of its leaf-related traits, supposed to be an important component for yield potential, remains elusive. Here, initially a set of chromosome segment substitution lines (CSSLs) was constructed, in which the genome of Pei-ai64S has been introgressed into the background of 93-11. This set was developed by marker aided selection, based on 123 polymorphic SSR markers. The introgressed chromosomal segments presented in the 156 CSSLs covered 96.46% of Pei-ai64S genome. Afterwards, the CSSLs were deployed to assess the genetic basis of leaf size (length and width) and chlorophyll content of top three leaves across five different environments. The CSSLs showed transgressive segregation for all of the traits, and significant correlations were detected among most of the traits. A total of 27 quantitative trait loci (QTL) were identified on ten chromosomes, and three QTL cluster affecting related traits were found on chromosome 3, 6, and 8, respectively. Remarkably, two key QTLs, qALW3-1 and qALW3-2, both controlling the antepenultimate leaf width, were identified in all five environments, and their effect were further validated by CSSLs harboring the two QTL alleles. Our results indicate that developing CSSLs is a powerful tool for genetic dissection of quantitative traits. Meanwhile, the QTLs controlling leaf-related traits uncovered here provide useful information for marker-assisted selection in improving the performance of leaf morphology and photosynthetic ability.

KLF9 promotes autophagy and apoptosis in T-cell acute lymphoblastic leukemia cells by inhibiting AKT/mTOR signaling pathway

Zhao Jie,He Shaolong,Xiang Chenhuan,Zhang Shaoli,Chen Xinyue,Lu Xinyi,Yao Qiong,Yang Liping,Ma Liangming,Tian Weiwei 대한독성 유전단백체 학회 2023 Molecular & cellular toxicology Vol.19 No.3

Background T -cell acute lymphoblastic leukemia (T-ALL) is considered a malignant tumor with a high mortality rate. To combat this disease, exploring the mechanism of T-ALL progression is urgently needed. Krüppel-like factors (KLFs) are known as the transcription factors and mediate series of biological processes. KLF9 is a member of the KLF family which could serve as a tumor suppressor gene in most solid tumors. GEO Database analysis showed that KLF9 expression in normal T cells was higher than T-ALL cell lines and patients. However, the possible role of KLF9 in T-ALL progression is still unclear. Objective To uncover the possible eff ects of Krüppel-like transcription factor 9 (KLF9) on the progression of T-Acute lymphoblastic leukemia (T-ALL). Results The expression of KLF9 was low in human T-ALL cells. KLF9 suppressed the viability of T-ALL cells. In addition, KLF9 stimulated the apoptosis as well as autophagy of T-ALL cells. Mechanically, KLF9 suppressed AKT/mTOR pathway in T-ALL cells. Conclusion KLF9 suppressed viability and promoted autophagy as well as apoptosis in T-ALL cells by inhibiting AKT/ mTOR pathway.

FLOURY ENDOSPERM8, encoding the UDP-glucose pyrophosphorylase 1, affects the synthesis and structure of starch in rice endosperm

Wuhua Long,Bangning Dong,Yihua Wang,Pengyi Pan,Yunlong Wang,Linglong Liu,Xiaoli Chen,Xi Liu,Shijia Liu,Yunlu Tian,Liangming Chen,Jianmin Wan 한국식물학회 2017 Journal of Plant Biology Vol.60 No.5

Cereal opaque-kernel mutants are ideal geneticmaterials for studying the mechanism of starch biosynthesisand amyloplast development. Here we isolated and identifiedtwo allelic floury endosperm 8 (flo8) mutants of rice, namedflo8-1 and flo8-2. In the flo8 mutant, the starch content wasdecreased and the normal physicochemical features ofstarch were altered. Map-based cloning and subsequentDNA sequencing analysis revealed a single nucleotidesubstitution and an 8-bp insertion occurred in UDP-glucosepyrophosphorylase 1 (Ugp1) gene in flo8-1 and flo8-2,respectively. Complementation of the flo8-1 mutant restorednormal seed appearance by expressing full length codingsequence of Ugp1. RT-qPCR analysis revealed that Ugp1was ubiquitously expressed. Mutation caused the decreasedUGPase activity and affected the expression of most of genesassociated with starch biosynthesis. Meanwhile, western blotand enzyme activity analyses showed the comparability ofprotein levels and enzyme activity of most tested starchbiosynthesis related genes. Our results demonstrate thatUgp1 plays an important role for starch biosynthesis in riceendosperm.