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"Cellular communication"
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Communication is key: extracellular vesicles as mediators of infection and defence during host–microbe interactions in animals and plants
ABSTRACT
Extracellular vesicles (EVs) are now understood to be ubiquitous mediators of cellular communication. In this review, we suggest that EVs have evolved into a highly regulated system of communication with complex functions including export of wastes, toxins and nutrients, targeted delivery of immune effectors and vectors of RNA silencing. Eukaryotic EVs come in different shapes and sizes and have been classified according to their biogenesis and size distributions. Small EVs (or exosomes) are released through fusion of endosome-derived multivesicular bodies with the plasma membrane. Medium EVs (or microvesicles) bud off the plasma membrane as a form of exocytosis. Finally, large EVs (or apoptotic bodies) are produced as a result of the apoptotic process. This review considers EV secretion and uptake in four eukaryotic kingdoms, three of which produce cell walls. The impacts cell walls have on EVs in plants and fungi are discussed, as are roles of fungal EVs in virulence. Contributions of plant EVs to development and innate immunity are presented. Compelling cases are sporophytic self-incompatibility and cellular invasion by haustorium-forming filamentous pathogens. The involvement of EVs in all of these eukaryotic processes is reconciled considering their evolutionary history.
Within the context of animal extracellular vesicles (EVs) and their interactions, recent developments in the growing fields of plant and fungal EVs suggest complex cross-kingdom communication with microbes for infection/protection.
Journal Article
Main Trends in the Development of Microwave Dielectric Materials for Cellular Communication Devices: A Review
The requirements for high-quality microwave (MW) dielectrics, which are used in the development of cellular communication devices (radio filters, solid-state generators, etc.) for the transition from 3G to 5G communication, are considered. The results of studies on important classes of MW dielectrics based on complex oxide systems of different crystal structures, such as potassium tungsten bronze, perovskite, pucherite, dreyerite, scheelite, as well as high-quality MW dielectrics with different permittivities, are systematized.
Journal Article
A resource allocation scheme for D2D communications with unknown channel state information
Device-to-device (D2D) communication is a dramatic departure from the conventional cellular architecture as it allows for user equipment (UE) in a cellular network to act as transmission relays without the involvement of network infrastructure, effectively realizing a co-existing massive ad-hoc network. While a hybrid D2D-cellular architecture can enhance the spectral efficiency, resource allocation in such a two-tier system is faced with unique challenges to ensure minimal impact on the performance of existing cellular users (CUs). In this paper, we address the D2D resource allocation problem under unknown channel state information (CSI). CSI-free schemes are substantial given that certain practical limitations (e.g., finite CSI feedback delay) make the knowledge of instantaneous CSI impossible in systems with fading channels. Also, statistical CSI needs pre-deployment training/model extraction and becomes invalid as the operating environment changes. Our proposed D2D resource optimization scheme for unknown CSI settings is applicable to a sub-class of scenarios which can be framed as the graph-theoretic weighted bipartite matching (WBM) problem. In the absence of CSI, WBM becomes a combinatorial problem with unknown random edge weights and generally unknown distributions. To compensate for this lack of knowledge, we resort to the formalism of combinatorial multi-armed bandit (CMAB) from machine learning theory. A CMAB-based network controller is able to reach optimal D2D configuration by following efficient rules which strike a balance between exploring alternative matchings and exploiting the gradually gained experience. We formulate and numerically experiment with two problems as “proof of concept”, namely (i) D2D relay selection, and (ii) joint mode selection and channel allocation. We also compare our results with existing/baseline schemes with various flavors of CSI availability assumptions, including perfect instantaneous CSI, perfect statistical CSI, erroneous CSI, and static CSI.
Journal Article
An Energy Efficient OFDM–MIMO Systems for Multimedia Data Transmission Based on Hybrid Fuzzy Approach
In a 4G cellular communication system, energy efficiency and power consumption are the key parameters in evaluating and designing communication system in multimedia. In this paper, an efficient model with high energy is proposed for multiple input multiple output orthogonal frequency division multiplexing (MIMO–OFDM) mobile multimedia systems with less power consumption. Providing high-speed video coding technique, which is designed to substantially improve coding efficiency compared with other coding techniques. Next to that erasures coding and Wyner–Ziv coding is used for encoding and compression process. Finally, efficient energy based optimized power allocation with hybrid Fuzzy Grey Wolf Optimization (GWO) algorithm is presented to reduce the power consumption of MIMO–OFDM mobile multimedia communication systems. The value of power which is consumed at the 30th iteration is 20 W and the energy efficiency is 92% for the 20 W power. Experimental results show that the proposed hybrid Fuzzy GWO algorithm can assure the required service with maximum efficiency in MIMO–OFDM.
Journal Article
Low probability of intercept-based adaptive radar waveform optimization in signal-dependent clutter for joint radar and cellular communication systems
In this paper, we investigate the problem of low probability of intercept (LPI)-based adaptive radar waveform optimization in signal-dependent clutter for joint radar and cellular communication systems, where the radar system optimizes the transmitted waveform such that the interference caused to the cellular communication systems is strictly controlled. Assuming that the precise knowledge of the target spectra, the power spectral densities (PSDs) of signal-dependent clutters, the propagation losses of corresponding channels and the communication signals is known by the radar, three different LPI based criteria for radar waveform optimization are proposed to minimize the total transmitted power of the radar system by optimizing the multicarrier radar waveform with a predefined signal-to-interference-plus-noise ratio (SINR) constraint and a minimum required capacity for the cellular communication systems. These criteria differ in the way the communication signals scattered off the target are considered in the radar waveform design: (1) as useful energy, (2) as interference or (3) ignored altogether. The resulting problems are solved analytically and their solutions represent the optimum power allocation for each subcarrier in the multicarrier radar waveform. We show with numerical results that the LPI performance of the radar system can be significantly improved by exploiting the scattered echoes off the target due to cellular communication signals received at the radar receiver.
Journal Article
Experimental Study of Fog and Suspended Water Effects on the 5G Millimeter Wave Communication Channel
Controlled experiments were conducted to examine the effect of fog on signal propagation in wireless communication and radar links operating in millimeter wavelengths. The experiments were carried out in a fog laboratory to verify theoretical results obtained from Liebe’s model. Attenuation and phase shifts of millimeter wave (mmW) radiation were measured, at different fog density characterized by the visibility distance and its water vapor content. Utilizing a vector network analyzer (VNA) enabled us to examine the actual atmospheric attenuation and the phase shift caused by the fog retardation. The experimental results demonstrate good agreement with the simulations even for very low visibility in highly dense fog. The study can be used to estimate link budget of mmW wireless links, including those allocated for the fifth generation (5G) of cellular networks.
Journal Article
Phototunable chip-scale topological photonics: 160 Gbps waveguide and demultiplexer for THz 6G communication
The revolutionary 5G cellular systems represent a breakthrough in the communication network design to provide a single platform for enabling enhanced broadband communications, virtual reality, autonomous driving, and the internet of everything. However, the ongoing massive deployment of 5G networks has unveiled inherent limitations that have stimulated the demand for innovative technologies with a vision toward 6G communications. Terahertz (0.1-10 THz) technology has been identified as a critical enabler for 6G communications with the prospect of massive capacity and connectivity. Nonetheless, existing terahertz on-chip communication devices suffer from crosstalk, scattering losses, limited data speed, and insufficient tunability. Here, we demonstrate a new class of phototunable, on-chip topological terahertz devices consisting of a broadband single-channel 160 Gbit/s communication link and a silicon Valley Photonic Crystal based demultiplexer. The optically controllable demultiplexing of two different carriers modulated signals without crosstalk is enabled by the topological protection and a critically coupled high-quality (
Q
) cavity. As a proof of concept, we demultiplexed high spectral efficiency 40 Gbit/s signals and demonstrated real-time streaming of uncompressed high-definition (HD) video (1.5 Gbit/s) using the topological photonic chip. Phototunable silicon topological photonics will augment complementary metal oxide semiconductor (CMOS) compatible terahertz technologies, vital for accelerating the development of futuristic 6G and 7G communication era driving the real-time terabits per second wireless connectivity for network sensing, holographic communication, and cognitive internet of everything.
6G communication requires high-speed and advanced functionalities on-chip. Here the authors demonstrate broadband phototunable topological waveguide and demultiplexing chip with record single-channel 160 Gbit/s communication link and excellent channel isolation for 300 GHz band.
Journal Article
Integrated analysis of the methylome and transcriptome of chickens with fatty liver hemorrhagic syndrome
Background
DNA methylation, a biochemical modification of cytosine, has an important role in lipid metabolism. Fatty liver hemorrhagic syndrome (FLHS) is a serious disease and is tightly linked to lipid homeostasis. Herein, we compared the methylome and transcriptome of chickens with and without FLHS.
Results
We found genome-wide dysregulated DNA methylation pattern in which regions up- and down-stream of gene body were hypo-methylated in chickens with FLHS. A total of 4155 differentially methylated genes and 1389 differentially expressed genes were identified. Genes were focused when a negative relationship between mRNA expression and DNA methylation in promoter and gene body were detected. Based on pathway enrichment analysis, we found expression of genes related to lipogenesis and oxygenolysis (e.g., PPAR signaling pathway, fatty acid biosynthesis, and fatty acid elongation) to be up-regulated with associated down-regulated DNA methylation. In contrast, genes related to cellular junction and communication pathways (e.g., vascular smooth muscle contraction, phosphatidylinositol signaling system, and gap junction) were inhibited and with associated up-regulation of DNA methylation.
Conclusions
In the current study, we provide a genome-wide scale landscape of DNA methylation and gene expression. The hepatic hypo-methylation feature has been identified with FLHS chickens. By integrated analysis, the results strongly suggest that increased lipid accumulation and hepatocyte rupture are central pathways that are regulated by DNA methylation in chickens with FLHS.
Journal Article
Reconfiguring wireless environments via intelligent surfaces for 6G: reflection, modulation, and security
The reconfigurable intelligent surface (RIS) has been recognized as an essential enabling technology for sixth-generation (6G) mobile communication networks. An RIS comprises a large number of small and low-cost reflecting elements whose parameters can be dynamically adjusted with a programmable controller. Each of these elements can effectively reflect a phase-shifted version of the incident electromagnetic wave. By configuring the wave phases in real time, the propagation environment of the information-bearing signals can be dynamically manipulated to enhance communication reliability, boost transmission rate, expand cellular coverage, and strengthen communication security. In this study, we provide an overview on RIS-assisted wireless communications. Specifically, we elaborate on the state-of-the-art enabling techniques for the RIS technology as well as their corresponding substantial benefits from the perspectives of RIS reflection and RIS modulation. With these benefits, we envision the integration of RISs into emerging applications for 6G. In addition, communication security is of unprecedented importance in future 6G networks with ubiquitous wireless services in multifarious verticals and areas. We highlight potential contributions of RISs to physical-layer security, in terms of secrecy rate and secrecy outage probability, exemplified by a typical case study from both theoretical and numerical aspects. Finally, we discuss challenges and opportunities on the deployment of RISs in practice to motivate future research.
Journal Article