Riga High Tech University

International audience

Astrophysical observations provide compelling evidence for gravitationally interacting dark matter in the universe that cannot be explained by the standard model of particle physics. The extraordinary amount of data from the CERN LHC presents a unique opportunity to shed light on the nature of dark matter at unprecedented collision energies. This Report comprehensively reviews the most recent searches with the CMS experiment for particles and interactions belonging to a dark sector and for dark-sector mediators. Models with invisible massive particles are probed by searches for signatures of missing transverse momentum recoiling against visible standard model particles. Searches for mediators are also conducted via fully visible final states. The results of these searches are compared with those obtained from direct-detection experiments. Searches for alternative scenarios predicting more complex dark sectors with multiple new particles and new forces are also presented. Many of these models include long-lived particles, which could manifest themselves with striking unconventional signatures with relatively small amounts of background. Searches for such particles are discussed and their impact on dark-sector scenarios is evaluated. Many results and interpretations have been newly obtained for this Report.

Recently developed hybrid assemblies can achieve telomere-to-telomere (T2T) completeness of some chromosomes. However, such approaches involve sequencing a large volume of both Pacific Biosciences high-fidelity (HiFi) and Oxford Nanopore Technologies (ONT) sequencing reads. Along with this, third-generation sequencing techniques are rapidly advancing, increasing the available length and accuracy. To reduce the final cost of genome assembly, here we investigated the possibility of assembly from low-coverage samples and with only ONT corrected by next-generation sequencing (NGS) sequencing reads. We demonstrated that haploid ONT-based assembly approaches corrected by NGS can achieve performance metrics comparable to more expensive hybrid approaches based on HiFi sequencing. We investigated the assembly of different chromosomes and the low-coverage performance of state-of-the-art hybrid assembly tools, including Verkko and Hifiasm, as well as ONT-based assemblers such as Shasta and Flye. We found that even with one-contig T2T assembly Verkko and Hifiasm still have numerous misassemblies within centromere. Therefore, we recommend using a combination of regular R9 or simplex R10 ONT reads and accurate NGS reads for assembly without aiming for T2T completeness. Additionally, we rigorously evaluated the performance of MGI, Illumina, and stLFR NGS technologies across various aspects of hybrid genome assembly, including pre-assembly correction, haplotype phasing, and polishing.

Riga street art map was made as a collaborative project by FaceBook group Ielu Mākslas mednieki (street art hunters). The group was created in September 2017 after an initial FB post by Agnese Aljena inviting people to create such map. Post went viral and soon the group reached 500+ members, all hunting street art in Riga and posting online their findings. It took about 2 months to create initial street art map covering most of the notable street art object of the city. Later new created artwork was added and identified destroyed art work is marked with black markers.

Abstract Phytophthora root and stem rot is one of the most aggressive diseases in soybean crop. The use of resistant cultivars is the main strategy to reduce losses caused by the pathogen. This study aims to identify SNP markers associated with genes or QTLs that provide soybean with partial resistance to Phytophthora sojae. A total of 169 soybean cultivars were inoculated with Phytophthora sojae and genotyped with 3,807 SNP markers. Genome-wide association analysis was carried out via multiple linear models, followed by multiple linear regression and linkage disequilibrium analysis. Four QTLs associated with the characteristic were identified: two on chromosome 3 and two on chromosome 15. The regions containing these QTLs contain genes already annotated as providers of resistance to pathogens, in plants. The use of those markers in the selection of resistant plants can increase the efficiency of breeding programs in the development of soybean varieties resistant to P. sojae.

Abstract Review: [91 refs.

The present article describes simulation results for single queue P/M/1/K model. Simulink has been used to create this model and evaluate its performance. The main purpose of the research made is to optimize costs of resources allocation for TCP traffic type at the same time striving to achieve the best packet loss probability. The optimization was made with dynamic programming method by using Bellman algorithm for simulated traffic with different self-similarity (Hurst) parameter and utilization coefficient values. The results of this work indicate that Hurst parameter affects greatly the costs of resources to be allocated. With estimation of Hurst parameter for network traffic these results can be used to estimate buffer memory capacity and ensure the specified value of packet loss probability. The research made also suggests to increase buffer memory capacity rather than channel bandwidth, whenever it is possible.

Water distribution networks require long term autonomous monitoring solutions, integrated, reliable and cost effective data transfer methods. This paper investigates the data delivery infrastructure of water distribution network sensor equipment used for network monitoring and billing of the subscribers. Water distribution network usually apply sensors to measure water flow, pressure and temperature. The main goal is to offer a wireless sensor system architecture comprising simplified and cost effective design for large scale deployments, maximizing autonomous running time and data transmission reliability. The proposed solution offers a periodic data acquisition system by removing the need of drive-by scenarios commonly used for water meter readouts collection. The idea of pseudo autonomous wireless sensor monitoring system is also discussed in the conclusion.

Abstract This provides the first examples of isoxazolyl sugars where the azole fragment is attached to C3 of the carbohydrate through a C—C bond.

The following paper examines problems in fast wireless data acquisition and proposes solution. The paper examines the area of autonomously controlled vehicles. Necessity of well-timed data in such an application is vital, since moving vehicle could damage itself and surroundings. As an example of such a task, authors use recent FP7 project - STRATOS. Existing solutions do not fulfill node amount and frequency requirements of the application. Solution contains all components, transmission technology, media access algorithm and gateway design. The key element for reaching requirements is using parallel data transmissions, along with time division media access (TDMA) algorithm. Testing and simulation proved that designed wireless sensor network that is capable of delivering measurements from 140 sensors with a frequency of 300Hz.