76 research outputs found
Plant-Mediated RNAi for Controlling Apolygus lucorum
The polyphagous mirid bug Apolygus lucorum (Heteroptera: Miridae) is a serious pest of agricultural crops in China, with more than 200 species of host plants including two very important crops, maize and soybean. Currently, prevention and control of A. lucorum rely mainly on chemical pesticides that cause environmental as well as health related problems. Plant-mediated RNAi has proven to offer great potential for pest control in the past decade. In this study, we screened and obtained seven candidate genes (Alucβ-actin, AlucV-ATPase-A/D/E, AlucEif5A, AlucEcR-A, AlucIAP) by injection-based RNAi which produced A. lucorum mortality rates of 46.01–82.32% at day 7 after injection. Among them, the plant-mediated RNAi of AlucV-ATPase-E was successfully introduced into transgenic maize and soybean, and the populations of A. lucorum were significantly decreased following feeding on the transgenic maize and soybean. These results are intended to provide helpful insight into the generation of bug-resistant plants through a plant-mediated RNAi strategy
The Impacts of Emission Control and Regional Transport on PM2.5 Ions and Carbon Components in Nanjing during the 2014 Nanjing Youth Olympic Games
Highly time-resolved measurements of water soluble ions, organic and elemental carbon concentrations in the particle diameter size range D-p <2.5 mu m (PM2.5) were performed at a downwind urban site in Nanjing in the western part of the Yangtze River Delta (YRD) in eastern China during the 2014 Youth Olympic Games (YOG). In this study, we discuss the impacts of emission control in Nanjing and the surrounding areas during the YOG and regional/long-range transport on PM2.5 pollution in Nanjing. The average concentrations of NO3-, SO42-, NH4+ were 12.1 +/- 9.9, 16.5 +/- 9.2, 9.0 +/- 5.4 mu g m(-3) during the YOG, and increased 34.3%, 53.7%, 43.9% after the YOG, respectively. The control of construction or on-road soil dust and control of industry led to the decrease of Ca2+ concentration by 55% and SO2 concentration by 46%. However, SO42- concentrations remained at relatively high levels, suggesting a significant impact of regional pollution to secondary fine particles in Nanjing. Strong correlations between OC and EC were observed during and after the YOG. A higher percentage (41%) of secondary organic carbon in Nanjing during the YOG periods was consistent with high potential photochemistry and low contributions from coal combustion. Lagrangian dispersion modelling results proved that the city clusters along the Nanjing and Shanghai axis were the major source region for high PM2.5 pollution in upwind Nanjing. This work shows that short-term strict control measures could improve the air quality, especially that affected by the primary pollutants; however, regional collaborative control strategy across administrative borders in the YRD is needed for a substantial improvement of air quality.Peer reviewe
Structure-Activity Relationship for the Oxadiazole Class of Antibiotics
The structure-activity relationship (SAR) for the newly discovered oxadiazole class of antibiotics is described with evaluation of 120 derivatives of the lead structure. This class of antibiotics was discovered by in silico docking and scoring against the crystal structure of a penicillin-binding protein. They impair cell-wall biosynthesis and exhibit activities against the Gram-positive bacterium Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA) and vancomycin-resistant and linezolid-resistant S. aureus. 5-(1H-Indol-5-yl)-3-(4-(4-(trifluoromethyl)phenoxy)phenyl)-1,2,4-oxadiazole (antibiotic 75b) was efficacious in a mouse model of MRSA infection, exhibiting a long half-life, a high volume of distribution, and low clearance. This antibiotic is bactericidal and is orally bioavailable in mice. This class of antibiotics holds great promise in recourse against infections by MRSA.Fil: Spink, Edward. University of Notre Dame-Indiana; Estados UnidosFil: Ding, Derong. University of Notre Dame-Indiana; Estados UnidosFil: Peng, Zhihong. University of Notre Dame-Indiana; Estados UnidosFil: Boudreau, Marc A.. University of Notre Dame-Indiana; Estados UnidosFil: Leemans, Erika. University of Notre Dame-Indiana; Estados UnidosFil: Lastochkin, Elena. University of Notre Dame-Indiana; Estados UnidosFil: Song, Wei. University of Notre Dame-Indiana; Estados UnidosFil: Lichtenwalter, Katerina. University of Notre Dame-Indiana; Estados UnidosFil: O’Daniel, Peter I.. University of Notre Dame-Indiana; Estados UnidosFil: Testero, Sebastian Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentina. University of Notre Dame-Indiana; Estados UnidosFil: Pi, Hualiang. University of Notre Dame-Indiana; Estados UnidosFil: Schroeder, Valerie A.. University of Notre Dame-Indiana; Estados UnidosFil: Wolter, William R.. University of Notre Dame-Indiana; Estados UnidosFil: Antunes, Nuno T.. University of Notre Dame-Indiana; Estados UnidosFil: Suckow, Mark A.. University of Notre Dame-Indiana; Estados UnidosFil: Vakulenko, Sergei. University of Notre Dame-Indiana; Estados UnidosFil: Chang, Mayland. University of Notre Dame-Indiana; Estados UnidosFil: Mobashery, Shahriar. University of Notre Dame-Indiana; Estados Unido
Structure-Activity Relationship for the Oxadiazole Class of Antibacterials
A structure-activity relationship (SAR) for the oxadiazole class of antibacterials was evaluated by syntheses of 72 analogs and determination of the minimal-inhibitory concentrations (MICs) against the ESKAPE panel of bacteria. Selected compounds were further evaluated for in vitro toxicity, plasma protein binding, pharmacokinetics (PK), and a mouse model of methicillin-resistant Staphylococcus aureus (MRSA) infection. Oxadiazole 72c shows potent in vitro antibacterial activity, exhibits low clearance, a high volume of distribution, and 41% oral bioavailability, and shows efficacy in mouse models of MRSA infection.Fil: Boudreau, Marc A.. University of Notre Dame; Estados UnidosFil: Ding, Derong. University of Notre Dame; Estados UnidosFil: Meisel, Jayda E.. University of Notre Dame; Estados UnidosFil: Janardhanan, Jeshina. University of Notre Dame; Estados UnidosFil: Spink, Edward. University of Notre Dame; Estados UnidosFil: Peng, Zhihong. University of Notre Dame; Estados UnidosFil: Qian, Yuanyuan. University of Notre Dame; Estados UnidosFil: Yamaguchi, Takao. University of Notre Dame; Estados UnidosFil: Testero, Sebastian Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentina. University of Notre Dame; Estados UnidosFil: O'Daniel, Peter I.. University of Notre Dame; Estados UnidosFil: Leemans, Erika. University of Notre Dame; Estados UnidosFil: Lastochkin, Elena. University of Notre Dame; Estados UnidosFil: Song, Wei. University of Notre Dame; Estados UnidosFil: Schroeder, Valerie A.. University of Notre Dame; Estados UnidosFil: Wolter, William R.. University of Notre Dame; Estados UnidosFil: Suckow, Mark A.. University of Notre Dame; Estados UnidosFil: Mobashery, Shahriar. University of Notre Dame; Estados UnidosFil: Chang, Mayland. University of Notre Dame; Estados Unido
An iterative adaptive dynamic programming algorithm for optimal control of unknown discrete-time nonlinear systems with constrained inputs
Causative agent distribution and antibiotic therapy assessment among adult patients with community acquired pneumonia in Chinese urban population
<p>Abstract</p> <p>Background</p> <p>Knowledge of predominant microbial patterns in community-acquired pneumonia (CAP) constitutes the basis for initial decisions about empirical antimicrobial treatment, so a prospective study was performed during 2003–2004 among CAP of adult Chinese urban populations.</p> <p>Methods</p> <p>Qualified patients were enrolled and screened for bacterial, atypical, and viral pathogens by sputum and/or blood culturing, and by antibody seroconversion test. Antibiotic treatment and patient outcome were also assessed.</p> <p>Results</p> <p>Non-viral pathogens were found in 324/610 (53.1%) patients among whom <it>M. pneumoniae </it>was the most prevalent (126/610, 20.7%). Atypical pathogens were identified in 62/195 (31.8%) patients carrying bacterial pathogens. Respiratory viruses were identified in 35 (19%) of 184 randomly selected patients with adenovirus being the most common (16/184, 8.7%). The nonsusceptibility of <it>S. pneumoniae </it>to penicillin and azithromycin was 22.2% (Resistance (R): 3.2%, Intermediate (I): 19.0%) and 79.4% (R: 79.4%, I: 0%), respectively. Of patients (312) from whom causative pathogens were identified and antibiotic treatments were recorded, clinical cure rate with β-lactam antibiotics alone and with combination of a β-lactam plus a macrolide or with fluoroquinolones was 63.7% (79/124) and 67%(126/188), respectively. For patients having mixed <it>M. pneumoniae </it>and/or <it>C. pneumoniae </it>infections, a better cure rate was observed with regimens that are active against atypical pathogens (e.g. a β-lactam plus a macrolide, or a fluoroquinolone) than with β-lactam alone (75.8% vs. 42.9%, <it>p </it>= 0.045).</p> <p>Conclusion</p> <p>In Chinese adult CAP patients, <it>M. pneumoniae </it>was the most prevalent with mixed infections containing atypical pathogens being frequently observed. With <it>S. pneumoniae</it>, the prevalence of macrolide resistance was high and penicillin resistance low compared with data reported in other regions.</p
Improving the Critic Learning for Event-Based Nonlinear H∞ Control Design
In this paper, we aim at improving the critic learning criterion to cope with the event-based nonlinear H∞ state feedback control design. First of all, the H∞ control problem is regarded as a two-player zero-sum game and the adaptive critic mechanism is used to achieve the minimax optimization under event-based environment. Then, based on an improved updating rule, the event-based optimal control law and the time-based worst-case disturbance law are obtained approximately by training a single critic neural network. The initial stabilizing control is no longer required during the implementation process of the new algorithm. Next, the closed-loop system is formulated as an impulsive model and its stability issue is handled by incorporating the improved learning criterion. The infamous Zeno behavior of the present event-based design is also avoided through theoretical analysis on the lower bound of the minimal intersample time. Finally, the applications to an aircraft dynamics and a robot arm plant are carried out to verify the efficient performance of the present novel design method
Intelligent Optimal Control with Critic Learning for a Nonlinear Overhead Crane System
In this paper, for achieving the discounted optimal feedback stabilization of a nonlinear overhead crane system, we establish an intelligent control strategy to obtain the solution of the corresponding Hamilton-Jacobi-Bellman equation. Specifically, neural networks are employed to serve as a necessary component to the control system, which exhibits strong online learning ability. A novel updating rule compared to the traditional adaptive critic algorithms is developed, which eliminates the requirement of the initial stabilizing controller and brings in unique advantages to the adaptive critic control design. Stability analysis of the closed-loop system based on the well-known Lyapunov approach and experimental simulation considering the nonlinear overhead dynamics with different case studies are performed to verify the effectiveness of the present control method both in theory and applications
Adaptive Critic Nonlinear Robust Control: A Survey
Adaptive dynamic programming (ADP) and reinforcement learning are quite relevant to each other when performing intelligent optimization. They are both regarded as promising methods involving important components of evaluation and improvement, at the background of information technology, such as artificial intelligence, big data, and deep learning. Although great progresses have been achieved and surveyed when addressing nonlinear optimal control problems, the research on robustness of ADP-based control strategies under uncertain environment has not been fully summarized. Hence, this survey reviews the recent main results of adaptive-critic-based robust control design of continuous-time nonlinear systems. The ADP-based nonlinear optimal regulation is reviewed, followed by robust stabilization of nonlinear systems with matched uncertainties, guaranteed cost control design of unmatched plants, and decentralized stabilization of interconnected systems. Additionally, further comprehensive discussions are presented, including event-based robust control design, improvement of the critic learning rule, nonlinear H∞ control design, and several notes on future perspectives. By applying the ADP-based optimal and robust control methods to a practical power system and an overhead crane plant, two typical examples are provided to verify the effectiveness of theoretical results. Overall, this survey is beneficial to promote the development of adaptive critic control methods with robustness guarantee and the construction of higher level intelligent systems
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