Pine wilt disease (PWD) caused by pine wood nematode (PWN), Bursaphelenchus xylophilus, is the most destructive diseases of pine and poses a threat of serious economic losses worldwide. Although several of the mechanisms involved in disease progression have been discovered, the molecular response of Pinus massoniana to PWN infection has not been explored. We constructed four subtractive suppression hybridization cDNA libraries by taking time-course samples from PWN-inoculated Masson pine trees. One-hundred forty-four significantly differentially expressed sequence tags (ESTs) were identified, and 124 high-quality sequences with transcriptional features were selected for gene ontology (GO) and individual gene analyses. There were marked differences in the types of transcripts, as well as in the timing and levels of transcript expression in the pine trees following PWN inoculation. Genes involved in signal transduction, transcription and translation and secondary metabolism were highly expressed after 24 h and 72 h, while stress response genes were highly expressed only after 72 h. Certain transcripts responding to PWN infection were discriminative; pathogenesis and cell wall-related genes were more abundant, while detoxification or redox process-related genes were less abundant. This study provides new insights into the molecular mechanisms that control the biochemical and physiological responses of pine trees to PWN infection, particularly during the initial stage of infection.

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Genetic response of human umbilical vein cells (HUVECs) to heat shock was studied using gene expression analysis. HUVECs were subjected to heat treatment at 44 degrees C and 55 degrees C for 1 h, respectively. Four hours after the treatment, gene expression of the treated cells and control cells (37 degrees C) were profiled using cDNA microarray. Data were analyzed using bioinformatics tools, and the results were verified by real-time quantitative PCR experiment. It has been shown that a large number of genes were regulated indicating global response to heat treatment at the genetic level.

The nodes of Wireless Sensor Network used in forest monitoring can not replace battery frequently, so they can not use disposable chemical battery with limited energy as traditional sensor network nodes. This article studied on the WSN node power system for forest monitoring, designed a node solar power system on the basis of analysis of the sensor node hardware and energy situation, and introduced the microprocessor control and software control flow of this system in detail. The solar power system was specifically designed to be capable of step-down and step-up the solar panel output DC (Direct current) voltage not only when the light is sufficient to meet the work requirements of each module of the sensor node, but also be able to step-up the output DC voltage when the solar cell was undervoltage in poor light to ensure the energy supply in light or low light environments, extending the service life of sensor nodes. Finally, simulation results are presented to show the feasibility of solar power system applied in WSN.

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The pine wood nematode (PWN), Bursaphelenchus xylophilus, is able to produce hundreds of thousands of offspring in a short time. Its mating behaviour might play a basic role in this marked fecundity. We investigated the features of the mating behaviour of B. xylophilus using long-time microscope video and repeated observations. The mating behaviour of B. xylophilus could be separated into a series of sequential sub-behaviours, including cruising, approaching, encountering, touching, hooping, locating, attaching, ejaculating, separating, quiescence and roaming. Overall, the process of mating behaviour could be divided into four different phases, searching, contacting, copulating and lingering; the mean times for these different phases varied significantly with 21.8 ± 2.0 min, 28.0 ± 1.9 min, 23.6 ± 0.7 min and 7.2 ± 0.5 min for each of the four phases, respectively. Attraction between the sexes was observed, indicating that sex pheromone(s) might be involved in mating behaviour of B. xylophilus. In addition, when one female was placed with three males, male-male competition was observed, which might be caused by mating-choice pressure from the female. Intra-sexual competition of females was also occasionally observed.

The integration of wireless local area network (WLAN) hotspot and the 3G cellular networks is imminently the future mode of public access networks. One of the key elements for the successful integration is vertical handoff between the two heterogeneous networks. Service disruption may occur during the vertical handoff because of the IP layer handoff activities, such as registration, binding update, routing table update, etc. In this paper, the network interface switching and registration process are proposed for the integrated WLAN/cellular network. Two types of fast vertical handoff protocols based on bicasting and non-bicasting supporting real-time traffic, such as voice over IP, are modeled. The performance of a bicasting based handoff scheme is analyzed and compared with that of fast handoff without bicasting. Numerical results and the simulation are given to show that packet loss rate can be reduced by the bicasting during handoff scheme without increasing bandwidth on both wireless interfaces. gateway GPRS supporting nodes (GGSNs), or 3G core network switches. Generally a loosely coupled network architecture, which is shown in Figure 1, is preferred [3] due to the flexible deployment and it is the network topology considered in the paper. In the figure, WLAN and 3G cellular networks work in a complementary way, and the interworking between WLAN and 3G cellular network is through an IP network. Mobile IP (MIP) protocol [4,5] is applied to support IP mobility for mobile nodes (MNs). The MNs are provided with MIP clients and can support both 802.11 and 3G cellular access technologies. Data can be transported between two different paths, shown as dashed lines in the figure, depending on the access interface that the MN is associated with. With this loosely coupled architecture, the same WLAN can be shared by different cellular service providers who own different 3G cellular networks. The main parts of a 3G cellular network owned by each service provider are radio access network (RAN) and core network. The network has two new functional entities, the home agent (HA) and the foreign agent (FA), specifically added to support MIP. The PDSN is modified to act as a FA for the cellular network in addition to its original intended functionality. 802.11 WLANs are connected through an IP network (or the Internet) to the 3G cellular core networks. Each WLAN has its own gateway which serves as a FA for MNs within its coverage. The authentication, authorization, and accounting (AAA) server is used for authentication and authorization of WLAN users as well as 3G cellular network users. Users registered with a cellular service provider is authenticated by the AAA/ RADIUS (remote authentication dial-in user service) server at the home network, whether accessing the network through the 3G cellular network section or the WLAN section.In loosely coupled WLAN/cellular networks, seamless service continuity is desired. Seamless service continuity requires that data loss and service break time during the vertical handoff between 3G c...

The present paper focuses on the application of the base station cooperation (BSC) technique in fractional frequency reuse (FFR) networks. Fractional frequency reuse is considered to be a promising scheme for avoiding the inter-cell interference problem in OFDMA cellular systems, such as WiMAX, in which the edge mobile stations (MSs) of adjacent cells use different subchannels for separate transmission. However, the problem of FFR is that the cell edge spectral efficiency (SE) is much lower than that of the cell center. The BSC technique, in which adjacent BSs perform cooperative transmission for one cell edge MS with the same channel, may improve the cell edge SE. However, since more BSs transmit signals for one cell edge MS, the use of BSC can also increase the inter-cell interference, which might degrade the network performance. In this paper, with a focus on this tradeoff, we propose an adaptive BSC scheme in which BSC is only performed for the cell edge MSs that can achieve a significant capacity increase with only a slight increase in intercell interference. Moreover, a channel reallocation scheme is proposed in order to further improve the performance of the adaptive BSC scheme. The simulation results reveal that, compared to the conventional FFR scheme, the proposed schemes are effective for improving the performance of FFR networks.