H<SUB>∞</SUB> Consensus for Heterogeneous Multi-agent Systems with Time-delay

Bei-Bei Wang,Yuan-Gong Sun 제어로봇시스템학회 2014 제어로봇시스템학회 국제학술대회 논문집 Vol.2014 No.10

In this paper, we consider the consensus and H∞ consensus problems of heterogeneous multi-agent systems composed of first-order and second-order integrator agents in directed networks with time-delay. Based on the graph theory and the reduced-order transformation, we first rewrite the heterogeneous multi-agent systems into the corresponding reduced-order systems. Then, we study the consensus of the heterogeneous multi-agent system with time-delay by using the linear matrix inequality method. As a result, sufficient conditions for consensus and H∞ consensus of heterogeneous multi-agent systems in terms of linear matrix inequalities are established. Finally, simulation results are provided to demonstrate the effectiveness of the main theoretical results.

Molecular insights into DNA interference by CRISPR-associated nuclease-helicase Cas3

Gong, Bei,Shin, Minsang,Sun, Jiali,Jung, Che-Hun,Bolt, Edward L.,van der Oost, John,Kim, Jeong-Sun National Academy of Sciences 2014 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.111 No.46

<P><B>Significance</B></P><P>Bacteria can repel invader DNA and RNA molecules by using an adaptive immunity mechanism called clustered regularly interspaced short palindromic repeats (CRISPRs)-Cas. CRISPR loci in a host genome are a repository of DNA fragments obtained from previous encounters with an invader, which can be transcribed and activated into short RNA molecules (crRNA) with sequences complementary to invader DNA or RNA. In some CRISPR-Cas systems, crRNA is assembled into a targeting complex called “Cascade” that seeks invader DNA to form an R-loop that triggers recruitment of a nuclease-helicase, Cas3, to destroy invader DNA. In this study, we show atomic resolution structures of a full-length Cas3, revealing how Cas3 coordinates binding, ATP-dependent translocation, and nuclease digestion of invader DNA.</P><P>Mobile genetic elements in bacteria are neutralized by a system based on clustered regularly interspaced short palindromic repeats (CRISPRs) and CRISPR-associated (Cas) proteins. Type I CRISPR-Cas systems use a “Cascade” ribonucleoprotein complex to guide RNA specifically to complementary sequence in invader double-stranded DNA (dsDNA), a process called “interference.” After target recognition by Cascade, formation of an R-loop triggers recruitment of a Cas3 nuclease-helicase, completing the interference process by destroying the invader dsDNA. To elucidate the molecular mechanism of CRISPR interference, we analyzed crystal structures of Cas3 from the bacterium <I>Thermobaculum terrenum</I>, with and without a bound ATP analog. The structures reveal a histidine-aspartate (HD)-type nuclease domain fused to superfamily-2 (SF2) helicase domains and a distinct C-terminal domain. Binding of ATP analog at the interface of the SF2 helicase RecA-like domains rearranges a motif V with implications for the enzyme mechanism. The HD-nucleolytic site contains two metal ions that are positioned at the end of a proposed nucleic acid-binding tunnel running through the SF2 helicase structure. This structural alignment suggests a mechanism for 3′ to 5′ nucleolytic processing of the displaced strand of invader DNA that is coordinated with ATP-dependent 3′ to 5′ translocation of Cas3 along DNA. In agreement with biochemical studies, the presented Cas3 structures reveal important mechanistic details on the neutralization of genetic invaders by type I CRISPR-Cas systems.</P>

Outcomes Based on Risk Assessment of Anastomotic Leakage after Rectal Cancer Surgery

Gong, Jian-Ping,Yang, Liu,Huang, Xin-En,Sun, Bei-Cheng,Zhou, Jian-Nong,Yu, Dong-Sheng,Zhou, Xin,Li, Dong-Zheng,Guan, Xin,Wang, Dong-Feng Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.2

Purpose: Anastomotic leakage (AL) is associated with high morbidity and mortality, high reoperation rates, and increased hospital length of stay. Here we investigated the risk factors for AL after anterior resection for rectal cancer with a double stapling technique. Patients and Methods: Data for 460 patients who underwent primary anterior resection with a double stapling technique for rectal carcinoma at a single institution from 2003 to 2007 were prospectively collected. All patients experienced a total mesorectal excision (TME) operation. Clinical AL was defined as the presence of leakage signs and confirmed by diagnostic work-up according to ICD-9 codes 997.4, 567.22 (abdominopelvic abscess), and 569.81 (fistula of the intestine). Univariate and logistic regression analyses of 20 variables were undertaken to determine risk factors for AL. Survival was analysed using the Cox regression method. Results: AL was noted in 35 (7.6%) of 460 patients with rectal cancer. :Median age of the patients was 65 (50-74) and 161 (35%) were male. The diagnosis of AL was made between the 6th and 12th postoperative day (POD; mean 8th POD). After univariate and multivariate analysis, age (p=0.004), gender (p=0.007), tumor site (p<0.001), preoperative body mass index (EMI) (p<0.001), the reduction of TSGF on 5th POD less than 10U/ml (p=0.044) and the pH value of pelvic dranage less than or equal to 6.978 on 3rd POD (p<0.001) were selected as 6 independent risk factors for AL. It was shown that significant differences in survival of the patients were AL-related (p<0.001), high ASA score related (p=0.036), high-level EMI related (p=0.007) and advanced TNM stage related <p<0.001). Conclusions: AL after anterior resection for rectal carcinoma is related to advanced age, low tumor site, male sex, high preoperative EMI, low pH value of pelvic drainage on POD 3 and a significant reduction of TSGF on POD 5. In addition to their high risk of immediate postoperative morbidity and mortality, AL, worse physical status, severe obesity and advanced TNM stage have similarly negative impact on survival.

Hidden Attribute Certificate-based Encryption Extensions Model

LI Yu,ZHAO Yong,GONG Bei,Xin Si-yuan 보안공학연구지원센터 2012 International Journal of Security and Its Applicat Vol.6 No.2

Physiological and biochemical characterization of sheepgrass (Leymus chinensis) reveals insights into photosynthetic apparatus coping with low-phosphate stress conditions

Lingyu Li,Haomeng Yang,Weibo Ren,Bei Liu,Dongmei Cheng,Xinhong Wu,Jirui Gong,Lianwei Peng,Fang Huang 한국식물학회 2016 Journal of Plant Biology Vol.59 No.4

Sheepgrass [Leymus chinensis (Trin.) Tzvel] is a valuble forage plant highly significant to regional grassland productivity of Euro-Asia steppes. Although effects of environmental stress including drought have been studied, impact of nutrient deficiency in particular phosphate (Pi), one of the essential macronutrient, is not reported. Here, we investigated low-Pi effect on its photosynthetic apparatus via physiological and biochemical analysis. We show that PSII activity was significantly reduced based on chlorophyll fluorescence measurements. We observed decreased amount of core proteins of PSII by immunoblot analysis. Further analysis of thylakoid membranes using 2D-BN/SDS-PAGE and immunoblot detection demonstrated that the amount of PSII complexes was closely correlated with the Pi levels within the range. Together with reduced number of thylakoid grana stackings observed, we suggest that the maintenance of PSII is impaired under Pi-limited condition. Moreover, enzyme activity assays revealed that the activity of several ROS scavenger enzymes was stimulated by low-Pi treatment. Based on these experimental results we conclude that PSII is the component of photosynthetic apparatus most sensitive to Pi supply and the enhanced anti-ROS activity is mainly subjective to protection of PSII against low Pi-induced photo-oxidative stress in the organism.

Effect of Matrix Metalloproteinase on Autolysis of Sea Cucumber Stichopus japonicus

Li-Ming Sun,Ting-Ting Wang,Bei-Wei Zhu,Hai-Ling Niu,Rui Zhang,Hong-Man Hou,Gong-Liang Zhang,Yoshiyuki Murata 한국식품과학회 2013 Food Science and Biotechnology Vol.22 No.5

To investigate the relationship between matrix metalloproteinase (MMPs) and autolysis of sea cucumber Stichopus japonicus, the dermis homogenate was incubated at 25oC to induce autolysis. EDTA Na2 and 1,10-phenanthroline were used to verify the effect of MMPs on autolysis, which was measured by soluble protein and protein pattern. Soluble protein level increased during a 6-h autolysis process. SDS-PAGE demonstrated obvious protein degradation with the concomitant occurrence of degradation products. The above two indicators could be inhibited significantly by EDTA Na2 and 1,10-phenanthroline, indicating that MMPs might play a significant role in autolysis of sea cucumber.

Current Evidence on the Association between rs3757318 of C6orf97 and Breast Cancer Risk: a Meta-Analysis

Hong, Yuan,Chen, Xue-Qin,Li, Jiao-Yuan,Liu, Cheng,Shen, Na,Zhu, Bei-Bei,Gong, Jing,Chen, Wei Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.19

Background: A common genetic variant rs3757318, located in intron of C6orf97, was firstly identified to be associated with breast cancer (BC) risk by a genome-wide association (GWA) study. However, subsequent validation studies with different ethnicities have yielded conflicting results. Materials and Methods: We performed a meta-analysis to synthesize all available data for evaluating the precise effect of this variant on BC susceptibility. Results: A total of 8 articles containing 11 studies with 62,891 cases and 65,635 controls were included in this meta-analysis. When compared to the G allele, the rs3757318-A allele was significantly associated with BC risk with the pooled OR of 1.21 (95% CI=1.15 - 1.29, P<0.001) but with obvious between-study heterogeneity (P=0.040). Stratified analysis suggested that diversity of ethnicity along with control source may explain part of the heterogeneity. Similarly, significant associations were also identified in heterozygote, homozygote, dominant and recessive genetic models. Sensitivity and publication bias analyses indicated robust stability of our results. Conclusions: Our present meta-analysis demonstrated that the variant rs3757318 is associated with increased BC risk. Nevertheless, further studies are needed to clarify the underlying biological mechanisms.