Coverage Optimization Strategy for WSN based on Energy-aware

In order to optimize the wireless sensor network coverage, this paper designs a coverage optimization strategy for wireless sensor network (EACS) based on energy-aware. Under the assumption that the geographic positions of sensor nodes are available, the proposed strategy consists of energy-aware and network coverage adjustment. It is restricted to conditions such as path loss, residual capacity and monitored area and according to awareness ability of sensors, it would adjust the monitored area, repair network hole and kick out the redundant coverage. The purpose is to balance the energy distribution of working nodes, reduce the number of “dead” nodes and balance network energy consumption. As a result, the network lifetime is expanded. Simulation results show that: EACS effectively reduces the number of working nodes, improves network coverage, lowers network energy consumption while ensuring the wireless sensor network coverage and connectivity, so as to balance network energy consumption

Prevalence and molecular characterization of oqxAB in clinical Escherichia coli isolates from companion animals and humans in Henan Province, China

Abstract Background The plasmid-encoded multidrug efflux pump oqxAB confers bacterial resistance primarily to olaquindox, quinolones, and chloramphenicol. The aims of this study were to investigate the prevalence of oqxAB among Escherichia coli isolates from dogs, cats, and humans in Henan, China and the susceptibilities of E. coli isolates to common antibiotics. Methods From 2012 to 2014, a total of 600 samples which included 400 rectal samples and 200 clinical human specimens were tested for the presence of E. coli. All isolates were screened for oqxAB genes by PCR and sequencing. The MICs of 11 antimicrobial agents were determined by the broth microdilution method. A total of 30 representative oqxAB-positive isolates were subjected to ERIC-PCR and MLST. Additionally, conjugation experiments and southern hybridizations were performed. Results Of 270 isolates, 58.5% (62/106) of the isolates from dogs, 56.25% (36/64) of the isolates from cats, and 42.0% (42/100) of the isolates from humans were positive for the oqxAB. Olaquindox resistance was found for 85.7%-100% of oqxAB-positive isolates. Of oqxAB-positive isolates from dogs, cats, and humans, ciprofloxacin resistance was inspected for 85.8%, 59.1%, and 93.8%, respectively. Several oqxAB-positive isolates were demonstrated by ERIC-PCR and MLST, and have high similarity. Phylogenetic analysis showed that oqxAB-positive isolates could be divided into 7 major clusters. OqxAB-positive conjugants were obtained, southern hybridization verified that the oqxAB gene complex was primarily located on plasmids. Conclusion In conclusion, oqxAB-positive isolates were widespread in animals and humans in Henan, China. Carriage of oqxAB on plasmids of E. coli isolates may facilitate the emergence of multidrug resistant and its transmission via horizontal transfer, and might pose a potential threat to public health

Additional file 1: Table S1. of Prevalence and molecular characterization of oqxAB in clinical Escherichia coli isolates from companion animals and humans in Henan Province, China

A list of the eleven tested antimicrobials, their classes, their concentrations, and their breakpoints used for susceptibility testing of E. coli. (DOC 58 kb