Modeling and Optimization of LoRa Networks under Multiple Constraints.

With the access of massive terminals of the Internet of Things (IoT), the low-power wide-area networks (LPWAN) applications represented by Long Range Radio (LoRa) will grow extensively in the future. The specific Long Range Wide Area Network (LoRaWAN) protocol within the LoRa network considers both low power consumption and long-range communication. It can optimize data transmission to achieve low communication latency, ensuring a responsive system and a favorable user experience. However, due to the limited resources in LoRa networks, if certain terminals have heavy traffic loads, it may result in unfair impacts on other terminals, leading to increased data transmission latency and disrupted operations for other terminals. Therefore, effectively optimizing resource allocation in LoRa networks has become a key issue in enhancing LoRa transmission performance. In this paper, a Mixed Integer Linear Programming (MILP) model is proposed to minimize network energy consumption under the maximization of user fairness as the optimization goal, which considers the constraints in the system to achieve adaptive resource allocation for spreading factor and transmission power. In addition, an efficient algorithm is proposed to solve this optimization problem by combining the Gurobi mathematical solver and heuristic genetic algorithm. The numerical results show that the proposed algorithm can significantly reduce the number of packet collisions, effectively minimize network energy consumption, as well as offering favorable fairness among terminals.

Passive Beamforming Design of IRS-Assisted MIMO Systems Based on Deep Learning.

In the intelligent reflecting surface (IRS)-assisted MIMO systems, optimizing the passive beamforming of the IRS to maximize spectral efficiency is crucial. However, due to the unit-modulus constraint of the IRS, the design of an optimal passive beamforming solution becomes a challenging task. The feature input of existing schemes often neglects to exploit channel state information (CSI), and all input data are treated equally in the network, which cannot effectively pay attention to the key information and features in the input. Also, these schemes usually have high complexity and computational cost. To address these issues, an effective three-channel data input structure is utilized, and an attention mechanism-assisted unsupervised learning scheme is proposed on this basis, which can better exploit CSI. It can also better exploit CSI by increasing the weight of key information in the input data to enhance the expression and generalization ability of the network. The simulation results show that compared with the existing schemes, the proposed scheme can effectively improve the spectrum efficiency, reduce the computational complexity, and converge quickly.

BIC2, a Cryptochrome Function Inhibitor, Is Involved in the Regulation of ABA Responses in Arabidopsis.

The plant hormone ABA (abscisic acid) is able to regulate plant responses to abiotic stresses via regulating the expression of ABA response genes. BIC1 (Blue-light Inhibitor of Cryptochromes 1) and BIC2 have been identified as the inhibitors of plant cryptochrome functions, and are involved in the regulation of plant development and metabolism in Arabidopsis . In this study, we report the identification of BIC2 as a regulator of ABA responses in Arabidopsis . RT-PCR (Reverse Transcription-Polymerase Chain Reaction) results show that the expression level of BIC1 remained largely unchanged, but that of BIC2 increased significantly in response to ABA treatment. Transfection assays in Arabidopsis protoplasts show that both BIC1 and BIC2 were mainly localized in the nucleus, and were able to activate the expression of the co-transfected reporter gene. Results in seed germination and seedling greening assays show that ABA sensitivity was increased in the transgenic plants overexpressing BIC2, but increased slightly, if any, in the transgenic plants overexpressing BIC1. ABA sensitivity was also increased in the bic2 single mutants in seedling greening assays, but no further increase was observed in the bic1 bic2 double mutants. On the other hand, in root elongation assays, ABA sensitivity was decreased in the transgenic plants overexpressing BIC2, as well as the bic2 single mutants, but no further decrease was observed in the bic1 bic2 double mutants. By using qRT-PCR (quantitative RT-PCR), we further examined how BIC2 may regulate ABA responses in Arabidopsis , and found that inhibition of ABA on the expression of the ABA receptor genes PYL4 (PYR1-Like 4) and PYL5 were decreased, but promotion of ABA on the expression of the protein kinase gene SnRK2.6 (SNF1-Related Protein Kinases 2.6) was enhanced in both the bic1 bic2 double mutants and 35S:BIC2 overexpression transgenic plants. Taken together, our results suggest that BIC2 regulates ABA responses in Arabidopsis possibly by affecting the expression of ABA signaling key regulator genes.

A case report of severe Fusobacterium nucleatum sepsis secondary to nephrectomy.

BACKGROUND: Fusobacterium nucleatum (F. nucleatum) is a resident anaerobic bacterium, which in rare cases may invade blood from the head and neck or the digestive tract to cause bacteremia and induce venous thrombosis. F. nucleatum is closely related to abdominal tumors, but it has not been reported in relation to renal tumors. We report herein a possible case. CASE PRESENTATION: This patient had kidney cancer with thrombosis in the right renal vein but had no sign of infection. After radical nephrectomy, thrombi formed in his left renal vein, and when removed, severe sepsis occurred. He did not respond to treatment with antibiotics and died, but the blood culture done confirmed that he had F. nucleatum bacteremia. CONCLUSION: F. nucleatum may also be associated with kidney cancer, and could cause post-operative renal vein thrombosis, and sepsis or septic shock after thrombectomy.

GCN5 modulates trichome initiation in Arabidopsis by manipulating histone acetylation of core trichome initiation regulator genes.

KEY MESSAGE: Histone acetyltransferase GCN5 affects trichome initiation via mediating the expression of some core trichome initiation regulator genes in Arabidopsis. GENERAL CONTROL NON-REPRESSED PROTEIN5 (GCN5), a histone acetyltransferase involved in the regulation of cell differentiation, organ development, secondary metabolism, and plant responses to abiotic stresses, has recently been shown to modulate trichome branching in Arabidopsis. Here, we provide evidence that GCN5 is also involved in the regulation of trichome initiation. We found that mutation of GCN5 led to increased leaf trichome density in Arabidopsis. Quantitative RT-PCR results showed that the expression of CPC, GL1, GL2, and GL3, four well-known core trichome initiation regulator genes, was decreased in the gcn5 mutants. ChIP assays indicated that these four trichome initiation regulator genes are direct targets of GCN5. Consistent with these results, GCN5-mediated H3K14/K9 acetylation levels on the TSS regions of these genes were decreased. On the other hand, leaf trichome density was reduced in plants overexpressing GCN5, and both the transcript levels and GCN5-binding enrichments of CPC, GL1, GL2, and GL3 genes were elevated. Taken together, these data suggests that GCN5 affects trichome initiation by modulating the transcription activities of trichome initiation regulator genes via H3K9/14 acetylation.

Involvement of PACLOBUTRAZOL RESISTANCE6/KIDARI, an Atypical bHLH Transcription Factor, in Auxin Responses in Arabidopsis.

Auxin regulates nearly all aspects of plant growth and development including cell division, cell elongation and cell differentiation, which are achieved largely by rapid regulation of auxin response genes. However, the functions of a large number of auxin response genes remain uncharacterized. Paclobutrazol Resistance (PRE) proteins are non-DNA binding basic helix-loop-helix transcription factors that have been shown to be involved in gibberellin and brassinosteroid signaling, and light responses in Arabidopsis. Here, we provide molecular and genetic evidence that PRE6, one of the six PRE genes in Arabidopsis, is an auxin response gene, and that PRE6 is involved in the regulation of auxin signaling. By using quantitative RT-PCR, we showed that the expression level of PRE6 was increased in response to exogenously applied IAA. GUS staining results also showed that the expression of GUS reporter gene in the PRE6p:GUS transgenic seedlings was elevated in response to auxin. Phenotypic analysis showed that overexpression of PRE6 in Arabidopsis resulted in auxin-related phenotypes including elongated hypocotyl and primary roots, and reduced number of lateral roots when compared with the Col wild type seedlings, whereas opposite phenotypes were observed in the pre6 mutants. Further analysis showed that PRE6 overexpression plants were hyposensitive, whereas pre6 mutants were hypersensitive to auxin in root and hypocotyl elongation and lateral root formation assays. By using protoplasts transfection, we showed that PRE6 functions as a transcriptional repressor. Consistent with this, the expression of the auxin response reporter DR5:GUS was decreased in PRE6 overexpression lines, but increased in pre6 mutants. When co-transfected into protoplasts, ARF5 and ARF8 activated the expression of the PRE6p:GUS reporter. Chromatin immunoprecipitation assays showed that ARF5 and ARF8 can be recruited to the promoter regions of PRE6. Taken together, these results suggest that PRE6 is an auxin response gene whose expression is directly regulated by ARF5 and ARF8, and that PRE6 is a transcriptional repressor that negatively regulates auxin responses in Arabidopsis.