SummaryModulation and suppression of the immune response of the host by nematode parasites have been reported extensively and the cysteine protease inhibitor (CPI or cystatin) is identified as one of the major immunomodulators. In the present study, we cloned and produced recombinant CPI protein from the murine nematode parasite Heligmosomoides polygyrus (rHp-CPI) and investigated its immunomodulatory effects on dendritic cell (DC) function and immune responses in mice. Bone-marrow-derived CD11c + DC (BMDC) that were exposed to rHp-CPI during the differentiation stage showed reduced MHC-II molecule expression compared with BMDC that were generated in normal culture conditions. The BMDC generated in the presence of rHp-CPI also exhibited reduced expression of CD40, CD86 and MHC-II molecules and reduced interleukin-6 and tumour necrosis factor-a cytokine production when stimulated with Tolllike receptor ligand CpG. Activation of BMDC generated in normal conditions induced by lipopolysaccharide and CpG was also suppressed by rHp-CPI, as shown by reduced co-stimulatory molecule expression and cytokine production. Furthermore, BMDC treated with rHp-CPI before ovalbumin (OVA) antigen pulsing induced a weaker proliferation response and less interferon-c production of OVA-specific CD4 + T cells compared with BMDC without rHp-CPI pre-treatment. Adoptive transfer of rHp-CPI-treated and OVA-loaded BMDC to mice induced significantly lower levels of antigen-specific antibody response than the BMDC loaded with antigen alone. These results demonstrated that the CPI from nematode parasites is able to modulate differentiation and activation stages of BMDC. It also interferes with antigen and MHC-II molecule processing and Toll-like receptor signalling pathway, resulting in functionally deficient DC that induce a suboptimum immune response.

The unmanned aerial vehicle (UAV) route planning problem mainly centralizes on the process of calculating the best route between the departure point and target point as well as avoiding obstructions on route to avoid collisions within a given flight area. A highly efficient route planning approach is required for this complex high dimensional optimization problem. However, many algorithms are infeasible or have low efficiency, particularly in the complex three-dimensional (3d) flight environment. In this paper, a modified sparrow search algorithm named CASSA has been presented to deal with this problem. Firstly, the 3d task space model and the UAV route planning cost functions are established, and the problem of route planning is transformed into a multi-dimensional function optimization problem. Secondly, the chaotic strategy is introduced to enhance the diversity of the population of the algorithm, and an adaptive inertia weight is used to balance the convergence rate and exploration capabilities of the algorithm. Finally, the Cauchy–Gaussian mutation strategy is adopted to enhance the capability of the algorithm to get rid of stagnation. The results of simulation demonstrate that the routes generated by CASSA are preferable to the sparrow search algorithm (SSA), particle swarm optimization (PSO), artificial bee colony (ABC), and whale optimization algorithm (WOA) under the identical environment, which means that CASSA is more efficient for solving UAV route planning problem when taking all kinds of constraints into consideration.

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With the development of wireless rechargeable sensor networks (WRSNs ), security issues of WRSNs have attracted more attention from scholars around the world. In this paper, a novel epidemic model, SILS(Susceptible, Infected, Low-energy, Susceptible), considering the removal, charging and reinfection process of WRSNs is proposed. Subsequently, the local and global stabilities of disease-free and epidemic equilibrium points are analyzed and simulated after obtaining the basic reproductive number R0. Detailedly, the simulations further reveal the unique characteristics of SILS when it tends to being stable, and the relationship between the charging rate and R0. Furthermore, the attack-defense game between malware and WRSNs is constructed and the optimal strategies of both players are obtained. Consequently, in the case of R0<1 and R0>1, the validity of the optimal strategies is verified by comparing with the non-optimal control group in the evolution of sensor nodes and accumulated cost.

SUMMARY In this paper, the problem of decentralized parameter estimation over noisy channels in a cluster‐based sensor network is studied. Each cluster head generates a local estimate by adopting a sample mean estimator. The local estimates from all cluster heads are compressed by using a one‐bit quantizer and then the bits are transmitted to a fusion center over independent binary symmetric channels. Two maximum likelihood estimators are proposed for estimating the parameter based on the received bits in two different scenarios: (i) all clusters have the same number of cluster members and (ii) the number of cluster members in the clusters are different. The Cramér–Rao lower bounds for the proposed estimators in both scenarios are derived. Simulation results show that the estimation performance for clustering with the same number of cluster members can be comparable to that for cluster‐free sensor networks. However, the estimation performance for clustering with a different number of cluster members is not as good as that for cluster‐free sensor networks. The trade off between estimation performance and energy consumption exists in both scenarios. The energy consumed for executing the estimation task in cluster‐based sensor networks is less than that in cluster‐free sensor networks. Copyright © 2011 John Wiley & Sons, Ltd.

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Laboratory populations of two Brachionus calyciflorus strains (WH and GZ strains) collected respectively from Zhujiang River and Changjiang River basins of China were cultured on 0.3 mglml of Chlorella pyrenoidosa, Scenedesmus obliquus or on a 1 : 1 mixture (wet weight) of the two algal species. The population growth rates of the WH and GZ strains fed C. pyrenoidosa were markedly higher than those fed on S. obliquus, but the body size (lorica length) and the egg size (egg volume) of both strains fed C. pyrenoidosa were significantly smaller than those fed on S. obliquus. When fed the same type of alga, the population growth rate of the WH strain was significantly higher than that of the GZ strain. However, the body size and the egg size of the WH strain were markedly smaller than those of the GZ strain. These results indicated that both strains were capable of varying their reproductive patterns, according to the algal food type, to maximize their reproductive rates; and, under the same culture condition, different rotifer strains possessed different reproductive strategies.