22 results on '"Sengupta, Avik"'
Search Results
2. Support Vector Machine-Based Prediction Models for Drug Repurposing and Designing Novel Drugs for Colorectal Cancer
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Sengupta, Avik, primary, Singh, Saurabh Kumar, additional, and Kumar, Rahul, additional
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- 2024
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3. Online Edge Caching and Wireless Delivery in Fog-Aided Networks with Dynamic Content Popularity
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Azimi, Seyyed Mohammadreza, Simeone, Osvaldo, Sengupta, Avik, and Tandon, Ravi
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Computer Science - Information Theory ,Computer Science - Networking and Internet Architecture - Abstract
Fog Radio Access Network (F-RAN) architectures can leverage both cloud processing and edge caching for content delivery to the users. To this end, F-RAN utilizes caches at the edge nodes (ENs) and fronthaul links connecting a cloud processor to ENs. Assuming time-invariant content popularity, existing information-theoretic analyses of content delivery in F-RANs rely on offline caching with separate content placement and delivery phases. In contrast, this work focuses on the scenario in which the set of popular content is time-varying, hence necessitating the online replenishment of the ENs' caches along with the delivery of the requested files. The analysis is centered on the characterization of the long-term Normalized Delivery Time (NDT), which captures the temporal dependence of the coding latencies accrued across multiple time slots in the high signal-to-noise ratio regime. Online edge caching and delivery schemes are investigated for both serial and pipelined transmission modes across fronthaul and edge segments. Analytical results demonstrate that, in the presence of a time-varying content popularity, the rate of fronthaul links sets a fundamental limit to the long-term NDT of F- RAN system. Analytical results are further verified by numerical simulation, yielding important design insights., Comment: 33 pages, 8 figures, Accepted for publication at IEEE Journal in Selected Areas in Communications, Special Issue on Caching for Communication Systems and Networks. arXiv admin note: text overlap with arXiv:1701.06188
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- 2017
4. Online Edge Caching in Fog-Aided Wireless Network
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Azimi, Seyyed Mohammadreza, Simeone, Osvaldo, Sengupta, Avik, and Tandon, Ravi
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Computer Science - Information Theory ,Computer Science - Networking and Internet Architecture - Abstract
In a Fog Radio Access Network (F-RAN) architecture, edge nodes (ENs), such as base stations, are equipped with limited-capacity caches, as well as with fronthaul links that can support given transmission rates from a cloud processor. Existing information-theoretic analyses of content delivery in F-RANs have focused on offline caching with separate content placement and delivery phases. In contrast, this work considers an online caching set-up, in which the set of popular files is time-varying and both cache replenishment and content delivery can take place in each time slot. The analysis is centered on the characterization of the long-term Normalized Delivery Time (NDT), which captures the temporal dependence of the coding latencies accrued across multiple time slots in the high signal-to- noise ratio regime. Online caching and delivery schemes based on reactive and proactive caching are investigated, and their performance is compared to optimal offline caching schemes both analytically and via numerical results., Comment: 20 pages, 5 figures, Please see the updated version arXiv:1711.10430
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- 2017
5. Artificially inserted strong promoter containing multiple Gquadruplexes induces long-range chromatin modification.
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Roy, Shuvra Shekhar, Bagri, Sulochana, Vinayagamurthy, Soujanya, Sengupta, Avik, Then, Claudia Regina, Kumar, Rahul, Sridharan, Sriram, and Chowdhury, Shantanu
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- 2024
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6. AagingBase: a comprehensive database of anti-aging peptides
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R, Kunjulakshmi, primary, Kumar, Ambuj, additional, Vinod Kumar, Keerthana, additional, Sengupta, Avik, additional, Kundal, Kavita, additional, Sharma, Simran, additional, Pawar, Ankita, additional, Krishna, Pithani Sai, additional, Alfatah, Mohammad, additional, Ray, Sandipan, additional, Tiwari, Bhavana, additional, and Kumar, Rahul, additional
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- 2024
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7. Improved Approximation of Storage-Rate Tradeoff for Caching with Multiple Demands
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Sengupta, Avik and Tandon, Ravi
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Computer Science - Information Theory ,Computer Science - Networking and Internet Architecture - Abstract
Caching at the network edge has emerged as a viable solution for alleviating the severe capacity crunch in modern content centric wireless networks by leveraging network load-balancing in the form of localized content storage and delivery. In this work, we consider a cache-aided network where the cache storage phase is assisted by a central server and users can demand multiple files at each transmission interval. To service these demands, we consider two delivery models - $(1)$ centralized content delivery where user demands at each transmission interval are serviced by the central server via multicast transmissions; and $(2)$ device-to-device (D2D) assisted distributed delivery where users multicast to each other in order to service file demands. For such cache-aided networks, we present new results on the fundamental cache storage vs. transmission rate tradeoff. Specifically, we develop a new technique for characterizing information theoretic lower bounds on the storage-rate tradeoff and show that the new lower bounds are strictly tighter than cut-set bounds from literature. Furthermore, using the new lower bounds, we establish the optimal storage-rate tradeoff to within a constant multiplicative gap. We show that, for multiple demands per user, achievable schemes based on repetition of schemes for single demands are order-optimal under both delivery models., Comment: Extended version of a submission to IEEE Trans. on Communications
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- 2016
8. Fog-Aided Wireless Networks for Content Delivery: Fundamental Latency Trade-Offs
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Sengupta, Avik, Tandon, Ravi, and Simeone, Osvaldo
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Computer Science - Information Theory ,Computer Science - Networking and Internet Architecture - Abstract
A fog-aided wireless network architecture is studied in which edge-nodes (ENs), such as base stations, are connected to a cloud processor via dedicated fronthaul links, while also being endowed with caches. Cloud processing enables the centralized implementation of cooperative transmission strategies at the ENs, albeit at the cost of an increased latency due to fronthaul transfer. In contrast, the proactive caching of popular content at the ENs allows for the low-latency delivery of the cached files, but with generally limited opportunities for cooperative transmission among the ENs. The interplay between cloud processing and edge caching is addressed from an information-theoretic viewpoint by investigating the fundamental limits of a high Signal-to-Noise-Ratio (SNR) metric, termed normalized delivery time (NDT), which captures the worst-case coding latency for delivering any requested content to the users. The NDT is defined under the assumptions of either serial or pipelined fronthaul-edge transmission, and is studied as a function of fronthaul and cache capacity constraints. Placement and delivery strategies across both fronthaul and wireless, or edge, segments are proposed with the aim of minimizing the NDT. Information-theoretic lower bounds on the NDT are also derived. Achievability arguments and lower bounds are leveraged to characterize the minimal NDT in a number of important special cases, including systems with no caching capabilities, as well as to prove that the proposed schemes achieve optimality within a constant multiplicative factor of 2 for all values of the problem parameters.
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- 2016
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9. Cache Aided Wireless Networks: Tradeoffs between Storage and Latency
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Sengupta, Avik, Tandon, Ravi, and Simeone, Osvaldo
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Computer Science - Information Theory - Abstract
We investigate the fundamental information theoretic limits of cache-aided wireless networks, in which edge nodes (or transmitters) are endowed with caches that can store popular content, such as multimedia files. This architecture aims to localize popular multimedia content by proactively pushing it closer to the edge of the wireless network, thereby alleviating backhaul load. An information theoretic model of such networks is presented, that includes the introduction of a new metric, namely normalized delivery time (NDT), which captures the worst case time to deliver any requested content to the users. We present new results on the trade-off between latency, measured via the NDT, and the cache storage capacity of the edge nodes. In particular, a novel information theoretic lower bound on NDT is presented for cache aided networks. The optimality of this bound is shown for several system parameters., Comment: 9 pages, 4 figures
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- 2015
10. Fundamental Limits of Caching with Secure Delivery
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Sengupta, Avik, Tandon, Ravi, and Clancy, T. Charles
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Computer Science - Information Theory ,Computer Science - Networking and Internet Architecture - Abstract
Caching is emerging as a vital tool for alleviating the severe capacity crunch in modern content-centric wireless networks. The main idea behind caching is to store parts of popular content in end-users' memory and leverage the locally stored content to reduce peak data rates. By jointly designing content placement and delivery mechanisms, recent works have shown order-wise reduction in transmission rates in contrast to traditional methods. In this work, we consider the secure caching problem with the additional goal of minimizing information leakage to an external wiretapper. The fundamental cache memory vs. transmission rate trade-off for the secure caching problem is characterized. Rather surprisingly, these results show that security can be introduced at a negligible cost, particularly for large number of files and users. It is also shown that the rate achieved by the proposed caching scheme with secure delivery is within a constant multiplicative factor from the information-theoretic optimal rate for almost all parameter values of practical interest.
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- 2013
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11. Real-world serological responses to extended-interval and heterologous COVID-19 mRNA vaccination in frail, older people (UNCoVER): an interim report from a prospective observational cohort study
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Vinh, Donald C, primary, Gouin, Jean-Philippe, additional, Cruz-Santiago, Diana, additional, Canac-Marquis, Michelle, additional, Bernier, Stéphane, additional, Bobeuf, Florian, additional, Sengupta, Avik, additional, Brassard, Jean-Philippe, additional, Guerra, Alyssa, additional, Dziarmaga, Robert, additional, Perez, Anna, additional, Sun, Yichun, additional, Li, Yongbiao, additional, Roussel, Lucie, additional, Langelier, Mélanie J, additional, Ke, Danbing, additional, Arnold, Corey, additional, Whelan, Marilyn, additional, Pelchat, Martin, additional, Langlois, Marc-André, additional, Zhang, Xun, additional, and Mazer, Bruce D, additional
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- 2022
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12. Unlocking Microsoft Office documents: an open source alternative
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Ackley, Ryan and Sengupta, Avik
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If you've ever written software to be used by business managers, you will no doubt have received requests for interoperability with the Microsoft Office Applications. 'Get me the report in […]
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- 2004
13. Fundamentals of Cache Aided Wireless Networks
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Sengupta, Avik, Electrical and Computer Engineering, Clancy, Thomas Charles III, Tandon, Ravi, Chen, Ing-Ray, Yang, Yaling, and Reed, Jeffrey H.
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Wireless Networks ,Content Delivery ,Caching - Abstract
Caching at the network edge has emerged as a viable solution for alleviating the severe capacity crunch in content-centric next generation 5G wireless networks by leveraging localized content storage and delivery. Caching generally works in two phases namely (i) storage phase where parts of popular content is pre-fetched and stored in caches at the network edge during time of low network load and (ii) delivery phase where content is distributed to users at times of high network load by leveraging the locally stored content. Cache-aided networks therefore have the potential to leverage storage at the network edge to increase bandwidth efficiency. In this dissertation we ask the following question - What are the theoretical and practical guarantees offered by cache aided networks for reliable content distribution while minimizing transmission rates and increasing network efficiency? We furnish an answer to this question by identifying fundamental Shannon-type limits for cache aided systems. To this end, we first consider a cache-aided network where the cache storage phase is assisted by a central server and users can demand multiple files at each transmission interval. To service these demands, we consider two delivery models - (i) centralized content delivery where demands are serviced by the central server; and (ii) device-to-device-assisted distributed delivery where demands are satisfied by leveraging the collective content of user caches. For such cache aided networks, we develop a new technique for characterizing information theoretic lower bounds on the fundamental storage-rate trade-off. Furthermore, using the new lower bounds, we establish the optimal storage-rate trade-off to within a constant multiplicative gap and show that, for the case of multiple demands per user, treating each set of demands independently is order-optimal. To address the concerns of privacy in multicast content delivery over such cache-aided networks, we introduce the problem of caching with secure delivery. We propose schemes which achieve information theoretic security in cache-aided networks and show that the achievable rate is within a constant multiplicative factor of the information theoretic optimal secure rate. We then extend our theoretical analysis to the wireless domain by studying a cloud and cache-aided wireless network from a perspective of low-latency content distribution. To this end, we define a new performance metric namely normalized delivery time, or NDT, which captures the worst-case delivery latency. We propose achievable schemes with an aim to minimize the NDT and derive information theoretic lower bounds which show that the proposed schemes achieve optimality to within a constant multiplicative factor of 2 for all values of problem parameters. Finally, we consider the problem of caching and content distribution in a multi-small-cell heterogeneous network from a reinforcement learning perspective for the case when the popularity of content is unknown. We propose a novel topology-aware learning-aided collaborative caching algorithm and show that collaboration among multiple small cells for cache-aided content delivery outperforms local caching in most network topologies of practical interest. The results presented in this dissertation show definitively that cache-aided systems help in appreciable increase of network efficiency and are a viable solution for the ever evolving capacity demands in the wireless communications landscape. Ph. D.
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- 2016
14. Fog-Aided Wireless Networks for Content Delivery: Fundamental Latency Tradeoffs
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Sengupta, Avik, primary, Tandon, Ravi, additional, and Simeone, Osvaldo, additional
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- 2017
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15. Improved Approximation of Storage-Rate Tradeoff for Caching With Multiple Demands
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Sengupta, Avik, primary and Tandon, Ravi, additional
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- 2017
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16. Julia High Performance
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Sengupta, Avik and Sengupta, Avik
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Design and develop high performing programs with JuliaAbout This BookLearn to code high reliability and high performance programsStand out from the crowd by developing code that runs faster than your peers' codesThis book is intended for developers who are interested in high performance technical programming.Who This Book Is ForThis book is for beginner and intermediate Julia programmers who are interested in high performance technical computing. You will have a basic familiarity with Julia syntax, and have written some small programs in the language.What You Will LearnDiscover the secrets behind Julia's speedGet a sense of the possibilities and limitations of Julia's performanceAnalyze the performance of Julia programsMeasure the time and memory taken by Julia programsCreate fast machine code using Julia's type informationDefine and call functions without compromising Julia's performanceUnderstand number types in JuliaUse Julia arrays to write high performance codeGet an overview of Julia's distributed computing capabilitiesIn DetailJulia is a high performance, high-level dynamic language designed to address the requirements of high-level numerical and scientific computing. Julia brings solutions to the complexities faced by developers while developing elegant and high performing code.Julia High Performance will take you on a journey to understand the performance characteristics of your Julia programs, and enables you to utilize the promise of near C levels of performance in Julia.You will learn to analyze and measure the performance of Julia code, understand how to avoid bottlenecks, and design your program for the highest possible performance. In this book, you will also see how Julia uses type information to achieve its performance goals, and how to use multuple dispatch to help the compiler to emit high performance machine code. Numbers and their arrays are obviously the key structures in scientific computing – you will see how Julia's design makes them fast. T
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- 2016
17. Julia: High Performance Programming
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Sengupta, Avik and Sengupta, Avik
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Leverage the power of Julia to design and develop high performing programsAbout This BookGet to know the best techniques to create blazingly fast programs with JuliaStand out from the crowd by developing code that runs faster than your peers' codeComplete an extensive data science project through the entire cycle from ETL to analytics and data visualizationWho This Book Is ForThis learning path is for data scientists and for all those who work in technical and scientific computation projects. It will be great for Julia developers who are interested in high-performance technical computing.This learning path assumes that you already have some basic working knowledge of Julia's syntax and high-level dynamic languages such as MATLAB, R, Python, or Ruby.What You Will LearnSet up your Julia environment to achieve the highest productivitySolve your tasks in a high-level dynamic language and use types for your data only when neededApply Julia to tackle problems concurrently and in a distributed environmentGet a sense of the possibilities and limitations of Julia's performanceUse Julia arrays to write high performance codeBuild a data science project through the entire cycle of ETL, analytics, and data visualizationDisplay graphics and visualizations to carry out modeling and simulation in JuliaDevelop your own packages and contribute to the Julia CommunityIn DetailIn this learning path, you will learn to use an interesting and dynamic programming language—Julia! You will get a chance to tackle your numerical and data problems with Julia. You'll begin the journey by setting up a running Julia platform before exploring its various built-in types. We'll then move on to the various functions and constructs in Julia. We'll walk through the two important collection types—arrays and matrices in Julia.You will dive into how Julia uses type information to achieve its performance goals, and how to use multiple dispatch to help the compiler emit high performance machine code. You will
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- 2016
18. Dynamic Resource Allocation for Cooperative Spectrum Sharing in LTE Networks
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Kumar, Akshay, primary, Sengupta, Avik, additional, Tandon, Ravi, additional, and Clancy, T. Charles, additional
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- 2015
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19. Redundant residue number system based space-time block codes
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Sengupta, Avik. and Sengupta, Avik.
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Space-time coding (STC) schemes for Multiple Input Multiple Output (MIMO) systems have been an area of active research in the past decade. In this thesis, we propose a novel design of Space-Time Block Codes (STBCs) using Redundant Residue Number System (RRNS) codes, which are ideal for high data rate communication systems. Application of RRNS as a concatenated STC scheme to a MIMO wireless communication system is the main motivation for this work. We have optimized the link between residues and complex constellations by incorporating the "Direct Mapping" scheme, where residues are mapped directly to Gray coded constellations. Knowledge of apriori probabilities of residues is utilized to implement a probability based "Distance-Aware Direct Mapping" (DA) scheme, which uses a set-partitioning approach to map the most probable residues such that they are separated by the maximum possible distance. We have proposed an "Indirect Mapping" scheme, where we convert the residues back to bits before mapping them. We have also proposed an adaptive demapping scheme which utilizes the RRNS code structure to reduce the ML decoding complexity and improve the error performance. We quantify the upper bounds on codeword and bit error probabilities of both Systematic and Non-systematic RRNS-STBC and characterize the achievable coding and diversity gains assuming maximum likelihood decoding (MLD). Simulation results demonstrate that the DA Mapping scheme provides performance gain relative to a Gray coded direct mapping scheme. We show that Systematic RRNS-STBC codes provide superior performance compared to Nonsystematic RRNS-STBC, for the same code parameters, owing to more efficient binary to residue mapping. When compared to other concatenated STBC and Orthogonal STBC (OSTBC) schemes, the proposed system gives better performance at low SNRs
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- 2012
20. System and method for heterogenous spectrum sharing between commercial cellular operators and legacy incumbent users in wireless networks
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Virginia Tech Intellectual Properties, Inc., FEDERATED WIRELESS, INC., Reed, Jeffrey H., Clancy, Thomas Charles III, Mitola, III, Joseph, Amanna, Ashwin, McGwier, Robert W., Kumar, Akshay, and Sengupta, Avik
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H04W72/02 ,H04W72/0453 ,H04W72/12 ,H04W28/16 ,H04W72/04 ,H04W88/08 ,H04W16/14 ,H04W84/042 ,H04W72/08 ,H04B17/318 ,H04W64/00 - Abstract
Described herein are systems and methods for telecommunications spectrum sharing between multiple heterogeneous users, which leverage a hybrid approach that includes both distributed spectrum sharing, spectrum-sensing, and use of geo-reference databases.
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- 2016
21. System and method for heterogenous spectrum sharing between commercial cellular operators and legacy incumbent users in wireless networks
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Electrical and Computer Engineering, Business Information Technology, Hume Center for National Security and Technology, Virginia Tech Intellectual Properties, Inc., Federated Wireless, Inc., Kumar, Akshay, Mitola, Joseph III, Reed, Jeffrey H., Clancy, Thomas Charles III, Amanna, Ashwin E., McGweir, Robert, and Sengupta, Avik
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H04W72/02 ,H04W72/0453 ,H04W72/12 ,H04W28/16 ,H04W72/04 ,H04W88/08 ,H04W16/14 ,H04W84/042 ,H04W72/08 ,H04B17/318 ,H04W64/00 - Abstract
Described herein are systems and methods for telecommunications spectrum sharing between multiple heterogeneous users, which leverage a hybrid approach that includes both distributed spectrum sharing, spectrum-sensing, and use of geo-reference databases.
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- 2013
22. Artificially inserted strong promoter containing multiple G-quadruplexes induces long-range chromatin modification.
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Roy SS, Bagri S, Vinayagamurthy S, Sengupta A, Then CR, Kumar R, Sridharan S, and Chowdhury S
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- Humans, Histones metabolism, Histones chemistry, Histones genetics, Enhancer Elements, Genetic, G-Quadruplexes, Promoter Regions, Genetic, Chromatin metabolism, Chromatin chemistry, Chromatin genetics
- Abstract
Although the role of G-quadruplex (G4) DNA structures has been suggested in chromosomal looping this was not tested directly. Here, to test causal function, an array of G4s, or control sequence that does not form G4s, were inserted within chromatin in cells. In vivo G4 formation of the inserted G4 sequence array, and not the control sequence, was confirmed using G4-selective antibody. Compared to the control insert, we observed a remarkable increase in the number of 3D chromatin looping interactions from the inserted G4 array. This was evident within the immediate topologically associated domain (TAD) and throughout the genome. Locally, recruitment of enhancer histone marks and the transcriptional coactivator p300/Acetylated-p300 increased in the G4-array, but not in the control insertion. Resulting promoter-enhancer interactions and gene activation were clear up to 5 Mb away from the insertion site. Together, these show the causal role of G4s in enhancer function and long-range chromatin interactions. Mechanisms of 3D topology are primarily based on DNA-bound architectural proteins that induce/stabilize long-range interactions. Involvement of the underlying intrinsic DNA sequence/structure in 3D looping shown here therefore throws new light on how long-range chromosomal interactions might be induced or maintained., Competing Interests: SR, SB, SV, AS, CT, RK, SS, SC No competing interests declared, (© 2024, Roy et al.)
- Published
- 2024
- Full Text
- View/download PDF
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