In this paper, we present an interference model for cognitive radio (CR) networks employing power control, contention control or hybrid power/contention control schemes. For the first case, a power control scheme is proposed to govern the transmission power of a CR node. For the second one, a contention control scheme at the media access control (MAC) layer, based on carrier sense multiple access with collision avoidance (CSMA/CA), is proposed to coordinate the operation of CR nodes with transmission requests. The probability density functions of the interference received at a primary receiver from a CR network are first derived numerically for these two cases. For the hybrid case, where power and contention controls are jointly adopted by a CR node to govern its transmission, the interference is analyzed and compared with that of the first two schemes by simulations. Then, the interference distributions under the first two control schemes are fitted by log-normal distributions with greatly reduced complexity. Moreover, the effect of a hidden primary receiver on the interference experienced at the receiver is investigated. It is demonstrated that both power and contention controls are effective approaches to alleviate the interference caused by CR networks. Some in-depth analysis of the impact of key parameters on the interference of CR networks is given via numerical studies as well.

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In this letter, we investigate the ergodic capacity of an uplink satellite network using a power-domain nonorthogonal multiple access (NOMA for simplicity) to serve users simultaneously in the consideration of random deployment of satellite users. Taking into account the deployed information of served users, we derive expression for the achievable ergodic capacity of the considered networks, where an entire link budget involving propagation loss, channel statistical prosperities, and location information is considered. Moreover, expression for ergodic capacity with OMA scheme is also derived to facilitate the performance comparison. Numerical simulation results are provided to attest the validity of theoretical results and show the vital effect of key parameters, such as the deployed information and link quality on the considered networks.

In this letter, we investigate the outage probability (OP) and ergodic capacity of downlink hybrid satellite terrestrial relay networks (HSTRNs) with a cooperative non-orthogonal multiple access (C-NOMA) scheme, in which a user with better channel condition acts as a relay node and forwards information to other users, thus alleviating the masking effect of users with poor channel conditions in heavy shadowing. Specifically, the exact analytical expression for the OP of the considered system is derived. Furthermore, the ergodic capacity expression is also developed to facilitate the performance evaluation of the proposed framework. Finally, simulations are provided to show the impact of key parameters on the considered system and the superiority of introducing the C-NOMA scheme to the HSTRNs. Index Terms-Hybrid satellite terrestrial relay networks, cooperative non-orthogonal multiple access, outage probability, ergodic capacity.

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The RNA-binding glycine-rich protein (RB-GRP) family is characterized by the presence of a glycine-rich domain arranged in (Gly)n-X repeats and an RNA-recognition motif (RRM). RB-GRPs participate in varied physiological and biochemical processes especially in the stress response of plants. In this study, a total of 23 RB-GRPs distributed on 10 chromosomes were identified in maize (Zea mays L.), and they were divided into four subgroups according to their conserved domain architecture. Five pairs of paralogs were identified, while none of them was located on the same chromosomal region, suggesting that segmental duplication is predominant in the duplication events of the RB-GRPs in maize. Comparative analysis of RB-GRPs in maize, Arabidopsis (Arabidopsis thaliana L.), rice (Oryza sativa L.), and wheat (Triticum aestivum) revealed that two exclusive subgroups were only identified in maize. Expression of eight ZmRB-GRPs was significantly regulated by at least two kinds of stresses. In addition, cis-elements predicted in the promoter regions of the ZmRB-GRPs also indicated that these ZmRB-GRPs would be involved in stress response of maize. The preliminary genome-wide analysis of the RB-GRPs in maize would provide useful information for further study on the function of the ZmRB-GRPs.

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