Enhancements for 5G NR PRACH Reception: An AI/ML Approach

Random Access is an important step in enabling the initial attachment of a User Equipment (UE) to a Base Station (gNB). The UE identifies itself by embedding a Preamble Index (RAPID) in the phase rotation of a known base sequence, which it transmits on the Physical Random Access Channel (PRACH). The signal on the PRACH also enables the estimation of propagation delay, often known as Timing Advance (TA), which is induced by virtue of the UE's position. Traditional receivers estimate the RAPID and TA using correlation-based techniques. This paper presents an alternative receiver approach that uses AI/ML models, wherein two neural networks are proposed, one for the RAPID and one for the TA. Different from other works, these two models can run in parallel as opposed to sequentially. Experiments with both simulated data and over-the-air hardware captures highlight the improved performance of the proposed AI/ML-based techniques compared to conventional correlation methods

Machine Learning Decoder for 5G NR PUCCH Format 0

5G cellular systems depend on the timely exchange of feedback control information between the user equipment and the base station. Proper decoding of this control information is necessary to set up and sustain high throughput radio links. This paper makes the first attempt at using Machine Learning techniques to improve the decoding performance of the Physical Uplink Control Channel Format 0. We use fully connected neural networks to classify the received samples based on the uplink control information content embedded within them. The trained neural network, tested on real-time wireless captures, shows significant improvement in accuracy over conventional DFT-based decoders, even at low SNR. The obtained accuracy results also demonstrate conformance with 3GPP requirements.Comment: Submitted to NCC conferenc

Genome fluctuations in cyanobacteria reflect evolutionary, developmental and adaptive traits

<p>Abstract</p> <p>Background</p> <p>Cyanobacteria belong to an ancient group of photosynthetic prokaryotes with pronounced variations in their cellular differentiation strategies, physiological capacities and choice of habitat. Sequencing efforts have shown that genomes within this phylum are equally diverse in terms of size and protein-coding capacity. To increase our understanding of genomic changes in the lineage, the genomes of 58 contemporary cyanobacteria were analysed for shared and unique orthologs.</p> <p>Results</p> <p>A total of 404 protein families, present in all cyanobacterial genomes, were identified. Two of these are unique to the phylum, corresponding to an AbrB family transcriptional regulator and a gene that escapes functional annotation although its genomic neighbourhood is conserved among the organisms examined. The evolution of cyanobacterial genome sizes involves a mix of gains and losses in the clade encompassing complex cyanobacteria, while a single event of reduction is evident in a clade dominated by unicellular cyanobacteria. Genome sizes and gene family copy numbers evolve at a higher rate in the former clade, and multi-copy genes were predominant in large genomes. Orthologs unique to cyanobacteria exhibiting specific characteristics, such as filament formation, heterocyst differentiation, diazotrophy and symbiotic competence, were also identified. An ancestral character reconstruction suggests that the most recent common ancestor of cyanobacteria had a genome size of approx. 4.5 Mbp and 1678 to 3291 protein-coding genes, 4%-6% of which are unique to cyanobacteria today.</p> <p>Conclusions</p> <p>The different rates of genome-size evolution and multi-copy gene abundance suggest two routes of genome development in the history of cyanobacteria. The expansion strategy is driven by gene-family enlargment and generates a broad adaptive potential; while the genome streamlining strategy imposes adaptations to highly specific niches, also reflected in their different functional capacities. A few genomes display extreme proliferation of non-coding nucleotides which is likely to be the result of initial expansion of genomes/gene copy number to gain adaptive potential, followed by a shift to a life-style in a highly specific niche (e.g. symbiosis). This transition results in redundancy of genes and gene families, leading to an increase in junk DNA and eventually to gene loss. A few orthologs can be correlated with specific phenotypes in cyanobacteria, such as filament formation and symbiotic competence; these constitute exciting exploratory targets.</p

Genome Sequence of Fusobacterium nucleatum Subspecies Polymorphum — a Genetically Tractable Fusobacterium

Fusobacterium nucleatum is a prominent member of the oral microbiota and is a common cause of human infection. F. nucleatum includes five subspecies: polymorphum, nucleatum, vincentii, fusiforme, and animalis. F. nucleatum subsp. polymorphum ATCC 10953 has been well characterized phenotypically and, in contrast to previously sequenced strains, is amenable to gene transfer. We sequenced and annotated the 2,429,698 bp genome of F. nucleatum subsp. polymorphum ATCC 10953. Plasmid pFN3 from the strain was also sequenced and analyzed. When compared to the other two available fusobacterial genomes (F. nucleatum subsp. nucleatum, and F. nucleatum subsp. vincentii) 627 open reading frames unique to F. nucleatum subsp. polymorphum ATCC 10953 were identified. A large percentage of these mapped within one of 28 regions or islands containing five or more genes. Seventeen percent of the clustered proteins that demonstrated similarity were most similar to proteins from the clostridia, with others being most similar to proteins from other gram-positive organisms such as Bacillus and Streptococcus. A ten kilobase region homologous to the Salmonella typhimurium propanediol utilization locus was identified, as was a prophage and integrated conjugal plasmid. The genome contains five composite ribozyme/transposons, similar to the CdISt IStrons described in Clostridium difficile. IStrons are not present in the other fusobacterial genomes. These findings indicate that F. nucleatum subsp. polymorphum is proficient at horizontal gene transfer and that exchange with the Firmicutes, particularly the Clostridia, is common

Subtle genetic changes enhance virulence of methicillin resistant and sensitive Staphylococcus aureus

<p>Abstract</p> <p>Background</p> <p>Community acquired (CA) methicillin-resistant <it>Staphylococcus aureus </it>(MRSA) increasingly causes disease worldwide. USA300 has emerged as the predominant clone causing superficial and invasive infections in children and adults in the USA. Epidemiological studies suggest that USA300 is more virulent than other CA-MRSA. The genetic determinants that render virulence and dominance to USA300 remain unclear.</p> <p>Results</p> <p>We sequenced the genomes of two pediatric USA300 isolates: one CA-MRSA and one CA-methicillin susceptible (MSSA), isolated at Texas Children's Hospital in Houston. DNA sequencing was performed by Sanger dideoxy whole genome shotgun (WGS) and 454 Life Sciences pyrosequencing strategies. The sequence of the USA300 MRSA strain was rigorously annotated. In USA300-MRSA 2658 chromosomal open reading frames were predicted and 3.1 and 27 kilobase (kb) plasmids were identified. USA300-MSSA contained a 20 kb plasmid with some homology to the 27 kb plasmid found in USA300-MRSA. Two regions found in US300-MRSA were absent in USA300-MSSA. One of these carried the arginine deiminase operon that appears to have been acquired from <it>S. epidermidis</it>. The USA300 sequence was aligned with other sequenced <it>S. aureus </it>genomes and regions unique to USA300 MRSA were identified.</p> <p>Conclusion</p> <p>USA300-MRSA is highly similar to other MRSA strains based on whole genome alignments and gene content, indicating that the differences in pathogenesis are due to subtle changes rather than to large-scale acquisition of virulence factor genes. The USA300 Houston isolate differs from another sequenced USA300 strain isolate, derived from a patient in San Francisco, in plasmid content and a number of sequence polymorphisms. Such differences will provide new insights into the evolution of pathogens.</p

Analysis of bifurcation patterns in reaction-diffusion systems: effect of external noise on the Brusselator model

Radical scavenging action of maleic anhydride (MA) is observed during chlorocarboxylation of polyethylene (PE) (CCPE). Reduction in the rate of chlorination is observed in the presence of MA in the CCPE process as compared to the rate of chlorination of PE (CPE) alone. Reduction in the rate of chlorination is due to the competitive nature of CCPE process and the radical scavenging action of MA. Radical scavenging action arises as a result of the formation of MA excimers of very short half life and their interactions with solvent. Other reactions responsible for scavenging action may also exist and are discussed. The kinetics of the scavenging process is studied by considering number of sites (N-0Cl), (N-Cl + N-MA) occupied during CPE and CCPE processes, respectively. The temperature dependence of the apparent rate constant kSCV is investigated and reveals that activation energy and pre-exponential factor are of the order of 10.3 kcal/mol and 9.1 s-1, respectively

Nodulation and effective nitrogen fixation of Macroptilium atropurpureum (siratro) by Burkholderia tuberum, a nodulating and plant growth promoting beta-proteobacterium, are influenced by environmental factors

Background and aims: Burkholderia tuberum STM678T was isolated from a South African legume, but did not renodulate this plant. Until a reliable host is found, studies on this and other interesting beta-rhizobia cannot advance. We investigated B. tuberum STM678T's ability to induce Fix+ nodules on a small-seeded, easy-to-propagate legume (Macroptilium atropurpureum). Previous studies demonstrated that B. tuberum elicited either Fix- or Fix+ nodules on siratro, but the reasons for this difference were unexplored. Methods: Experiments to promote effective siratro nodule formation under different environmental conditions were performed. B. tuberum STM678T's ability to withstand high temperatures and desiccation was checked as well as its potential for promoting plant growth via mechanisms in addition to nitrogen fixation, e.g., phosphate solubilization and siderophore production. Potential genes for these activities were found in the sequenced genomes. Results: Higher temperatures and reduced watering resulted in reliable, effective nodulation on siratro. Burkholderia spp. solubilize phosphate and produce siderophores. Genes encoding proteins potentially involved in these growth-promoting activities were detected and are described. Conclusions: Siratro is an excellent model plant for B. tuberum STM678T. We identified genes that might be involved in the ability of diazotrophic Burkholderia species to survive harsh conditions, solubilize phosphate, and produce siderophores. © 2013 Springer Science+Business Media Dordrecht