Abstract-Over the last decade, the growing amount of UL and DL mobile data traffic has been characterized by substantial asymmetry and time variations. Dynamic time-division duplex (TDD) has the capability to accommodate to the traffic asymmetry by adapting the UL/DL configuration to the current traffic demands. In this work, we study a two-tier heterogeneous cellular network (HCN) where the macro tier and small cell tier operate according to a dynamic TDD scheme on orthogonal frequency bands. To offload the network infrastructure, mobile users in proximity can engage in D2D communications, whose activity is determined by a carrier sensing multiple access (CSMA) scheme to protect the ongoing infrastructure-based and D2D transmissions. We present an analytical framework to evaluate the network performance in terms of load-aware coverage probability and network throughput. The proposed framework allows to quantify the effect on the coverage probability of the most important TDD system parameters, such as the UL/DL configuration, the base station density, and the bias factor. In addition, we evaluate how the bandwidth partition and the D2D network access scheme affect the total network throughput. Through the study of the tradeoff between coverage probability and D2D user activity, we provide guidelines for the optimal design of D2D network access.

Background: The gene encoding the E3 ubiquitin ligase substrate-binding adaptor SPOP is frequently mutated in primary prostate cancer, but how SPOP mutations contribute to prostate cancer pathogenesis remains poorly understood. Stress granules (SG) assembly is an evolutionarily conserved strategy for survival of cells under stress, and often upregulated in human cancers. We investigated the role of SPOP mutations in aberrant activation of the SG in prostate cancer and explored the relevanve of the mechanism in therapy resistance. Methods: We identified SG nucleating protein Caprin1 as a SPOP interactor by using the yeast two hybrid methods. A series of functional analyses in cell lines, patient samples, and xenograft models were performed to investigate the biological significance and clinical relevance of SPOP regulation of SG signaling in prostate cancer. Results: The cytoplasmic form of wild-type (WT) SPOP recognizes and triggers ubiquitin-dependent degradation of Caprin1. Caprin1 abundance is elevated in SPOP-mutant expressing prostate cancer cell lines and patient specimens. SPOP WT suppresses SG assembly, while the prostate cancer-associated mutants enhance SG assembly in a Caprin1dependent manner. Knockout of SPOP or expression of prostate cancer-associated SPOP mutants conferred resistance to death caused by SG inducers (e.g. docetaxel, sodium arsenite and H 2 O 2) in prostate cancer cells. Conclusions: SG assembly is aberrantly elevated in SPOP-mutated prostate cancer. SPOP mutations cause resistance to cellular stress induced by chemtherapeutic drug such as docetaxel in prostate cancer.

Background Cotton fiber length and strength are both key traits of fiber quality, and fiber strength (FS) is tightly correlated with secondary cell wall (SCW) biosynthesis. The three-amino-acid-loop-extension (TALE) superclass homeoproteins are involved in regulating diverse biological processes in plants, and some TALE members has been identified to play a key role in regulating SCW formation. However, little is known about the functions of TALE members in cotton (Gossypium spp.). Results In the present study, based on gene homology, 46, 47, 88 and 94 TALE superfamily genes were identified in G. arboreum, G. raimondii, G. barbadense and G. hirsutum, respectively. Phylogenetic and evolutionary analysis showed the evolutionary conservation of two cotton TALE families (including BEL1-like and KNOX families). Gene structure analysis also indicated the conservation of GhTALE members under selection. The analysis of promoter cis-elements and expression patterns suggested potential transcriptional regulation functions in fiber SCW biosynthesis and responses to some phytohormones for GhTALE proteins. Genome-wide analysis of colocalization of TALE transcription factors with SCW-related QTLs revealed that some BEL1-like genes and KNAT7 homologs may participate in the regulation of cotton fiber strength formation. Overexpression of GhKNAT7-A03 and GhBLH6-A13 significantly inhibited the synthesis of lignocellulose in interfascicular fibers of Arabidopsis. Yeast two-hybrid (Y2H) experiments showed extensive heteromeric interactions between GhKNAT7 homologs and some GhBEL1-like proteins. Yeast one-hybrid (Y1H) experiments identified the upstream GhMYB46 binding sites in the promoter region of GhTALE members and defined the downstream genes that can be directly bound and regulated by GhTALE heterodimers. Conclusion We comprehensively identified TALE superfamily genes in cotton. Some GhTALE members are predominantly expressed during the cotton fiber SCW thicking stage, and may genetically correlated with the formation of FS. Class II KNOX member GhKNAT7 can interact with some GhBEL1-like members to form the heterodimers to regulate the downstream targets, and this regulatory relationship is partially conserved with Arabidopsis. In summary, this study provides important clues for further elucidating the functions of TALE genes in regulating cotton growth and development, especially in the fiber SCW biosynthesis network, and it also contributes genetic resources to the improvement of cotton fiber quality.