Control of divergent noncoding transcription in Saccharomyces cerevisiae

The regulation of gene expression underlies all cellular processes and fundamentally enables complexity of eukaryotic organisms. Aberrant expression of noncoding RNAs can compromise normal gene expression. Gene promoters are inherently bidirectional and generate divergent noncoding RNAs along with protein-coding messenger RNAs. Chromatin and RNA turnover pathways limit expression of noncoding RNAs, but how sequence-specific transcription factors regulate divergent noncoding transcription and promoter directionality is not well understood. Here, I investigate how divergent transcription is repressed at highly expressed genes in Saccharomyces cerevisiae. I find that the sequence-specific transcription factor Rap1 limits divergent noncoding transcription at a large fraction of its target genes. Rap1 safeguards normal gene expression by limiting aberrant transcription that overlaps with neighbouring loci. Divergent RNAs initiate at or extremely close to Rap1 binding sites, indicating that Rap1 limits initiation of transcription from divergent core promoters. Stable binding of Rap1 near cryptic promoters is required and sufficient to suppress divergent transcription. Silencing cofactors or transcriptional coactivators associated with Rap1 are not required for repression of noncoding RNAs at promoters. In contrast, a small region within the Rap1 carboxy-terminal domain is required for repression of divergent transcription and affects interaction between Rap1 and the RSC chromatin remodeller. RSC and Rap1 regulate divergent transcription at Rap1-regulated gene promoters in distinct ways. Promoter output shifts from unidirectional to bidirectional transcription in the absence of Rap1, which is partially suppressed after co-depletion of Rap1 and RSC. RSC activity is not strictly required for divergent transcription suggesting that additional regulators also play important roles. I propose that certain sequence-specific transcription factors limit the access of transcription machinery and coactivators to divergent core promoters by steric hindrance, thereby providing directionality towards productive transcription of coding genes

Energy-Efficient NOMA Enabled Heterogeneous Cloud Radio Access Networks

Heterogeneous cloud radio access networks (H-CRANs) are envisioned to be promising in the fifth generation (5G) wireless networks. H-CRANs enable users to enjoy diverse services with high energy efficiency, high spectral efficiency, and low-cost operation, which are achieved by using cloud computing and virtualization techniques. However, H-CRANs face many technical challenges due to massive user connectivity, increasingly severe spectrum scarcity and energy-constrained devices. These challenges may significantly decrease the quality of service of users if not properly tackled. Non-orthogonal multiple access (NOMA) schemes exploit non-orthogonal resources to provide services for multiple users and are receiving increasing attention for their potential of improving spectral and energy efficiency in 5G networks. In this article a framework for energy-efficient NOMA H-CRANs is presented. The enabling technologies for NOMA H-CRANs are surveyed. Challenges to implement these technologies and open issues are discussed. This article also presents the performance evaluation on energy efficiency of H-CRANs with NOMA.Comment: This work has been accepted by IEEE Network. Pages 18, Figure

Corporate E-banking: A Study based on DeLone and McLean’s IS Success Model

Although there are ample of studies dealing with retail internet banking, very few studies have investigated corporate internet banking. The objective of the current research is to study the determinants of the intention to continue use online banking of the existing corporate customers. This study collected data from 154 customers of an international bank to test a model developed from the DeLone and McLean’s IS success model. The results show that system quality contributes most to the perception of overall quality of the corporate e-banking service as well as the impact on the future use intention. Other factors that are found to be important are human service quality, information quality, and accuracy and security of the system

A Survey of Physical Layer Security Techniques for 5G Wireless Networks and Challenges Ahead

Physical layer security which safeguards data confidentiality based on the information-theoretic approaches has received significant research interest recently. The key idea behind physical layer security is to utilize the intrinsic randomness of the transmission channel to guarantee the security in physical layer. The evolution towards 5G wireless communications poses new challenges for physical layer security research. This paper provides a latest survey of the physical layer security research on various promising 5G technologies, including physical layer security coding, massive multiple-input multiple-output, millimeter wave communications, heterogeneous networks, non-orthogonal multiple access, full duplex technology, etc. Technical challenges which remain unresolved at the time of writing are summarized and the future trends of physical layer security in 5G and beyond are discussed.Comment: To appear in IEEE Journal on Selected Areas in Communication

Joint Channel-and-Data Estimation for Large-MIMO Systems with Low-Precision ADCs

The use of low precision (e.g., 1-3 bits) analog-to-digital convenors (ADCs) in very large multiple-input multiple-output (MIMO) systems is a technique to reduce cost and power consumption. In this context, nevertheless, it has been shown that the training duration is required to be {\em very large} just to obtain an acceptable channel state information (CSI) at the receiver. A possible solution to the quantized MIMO systems is joint channel-and-data (JCD) estimation. This paper first develops an analytical framework for studying the quantized MIMO system using JCD estimation. In particular, we use the Bayes-optimal inference for the JCD estimation and realize this estimator utilizing a recent technique based on approximate message passing. Large-system analysis based on the replica method is then adopted to derive the asymptotic performances of the JCD estimator. Results from simulations confirm our theoretical findings and reveal that the JCD estimator can provide a significant gain over conventional pilot-only schemes in the quantized MIMO system.Comment: 7 pages, 4 figure

An Aircraft Service Staff Rostering using a Hybrid GRASP Algorithm

The aircraft ground service company is responsible for carrying out the regular tasks to aircraft maintenace between their arrival at and departure from the airport. This paper presents the application of a hybrid approach based upon greedy randomized adaptive search procedure (GRASP) for rostering technical staff such that they are assigned predefined shift patterns. The rostering of staff is posed as an optimization problem with an aim of minimizing the violations of hard and soft constraints. The proposed algorithm iteratively constructs a set of solutions by GRASP. Furthermore, with multi-agent techniques, we efficiently identify an optimal roster with minimal constraint violations and fair to employees. Experimental results are included to demonstrate the effectiveness of the proposed algorithm

How visual feedback affects movements

Monkeys were well trained to perform a variety of point-to-point reaching movements in virtual reality. We systematically varied the timing and location of the visualized hand position to study the way that visual feedback is used during the initial phase of reaching. The results showed that the monkey learned a discrete strategy based on the information from vision of the hand during the reach. This information was used in a different phase of the task after a stereotypic processing delay to reach the target correctly. Here, I demonstrate that reaching movement was affected by a gradual and orderly changed flash distance (at which point the flash was shown), but it was not affected when the order of the flash distance was randomly assigned. This suggested that the flash could not create a clear effect to the reaching every time. Second, I have show that a misplaced location of flash could not make the hand produce the hypothetical adjustment which counterbalanced the perceived error. This suggested that the flash had to contain correct information in order to be used by the monkey. Finally, I showed that the monkey was able to utilize the flash in the spatial rotation center-out task (the flash was displaced to either side of its proper location). This paper provides a novel behavior task for monkeys' movement correction experiment, and it is a useful tool to achieve the long-term goals of understanding the connection between M1 neurons and early correction stimulus