scholarly journals Tandemly repeated trinucleotides - comparative analysis.

2006 ◽  
Vol 53 (2) ◽  
pp. 279-287 ◽  
Author(s):  
Monika Piwowar ◽  
Jan Meus ◽  
Piotr Piwowar ◽  
Zdzisław Wiśniowski ◽  
Justyna Stefaniak ◽  
...  

Characteristics of 64 possible tandem trinucleotide repeats (TSSR) from Homo sapiens (hs), Mus musculus (mm) and Rattus norvegicus (rn) genomes are presented. Comparative analysis of TSSR frequency depending on their repetitiveness and similarity of the TSSR length distributions is shown. Comparative analysis of TSSR sequence motifs and association between type of motif and its length (n) using rho-coefficient method (quantitatively measuring the association between variables in contingency tables) is presented. These analyses were carried out in the context of neurodegenerative diseases based on trinucleotide tandems. The length of these tandems and their relation to other TSSR is estimated. It was found that the higher repetitiveness (n) the lower frequency of trinucleotides tandems. Differences between genomes under consideration, especially in longer than n=9 TSSR were discussed. A significantly higher frequency off A- and T-rich tandems is observed in the human genome (as well as in human mRNA). This observation also applies to mm and rn, although lower abundant in proportion to human genomes was found. The origin of elongation (or shortening) of TSSR seems to be neither frequency nor length dependent. The results of TSSR analysis presented in this work suggest that neurodegenerative disease-related microsatellites do not differ versus the other except the lower frequency versus the other TSSR. CAG occurs with relatively high frequency in human mRNA, although there are other TSSR with higher frequency that do not cause comparable disease disorders. It suggests that the mechanism of TSSR instability is not the only origin of neurodegenerative diseases.

2012 ◽  
Vol 622-623 ◽  
pp. 1670-1673
Author(s):  
Ye Wu ◽  
Bo Zhang ◽  
Jia Wei

A new wavelet extension de-noising (WED) method is proposed in this paper. The basic principle is derived in detail. We have removed the high frequency noise in seismic data based on the suppressing detail components method, Fourier transform filtering method, WED method and reconstructing the 5th layer approximate coefficient method respectively, and the results show that the WED method can more effectively restrain noise than the other methods.


Author(s):  
E. Faghand ◽  
S. Karimian ◽  
E. Mehrshahi ◽  
N. Karimian

Abstract A new simple computational tool is proposed for the synthesis of multi-section coupled-line filters based on combined modified planar circuit method (MPCM) and transmission line method (TLM) analysis, referred to as MPCM-TLM. Due to its fundamentally simple architecture, the presented tool offers significantly faster optimization of coupled-line filters – for exactly the same initial simulation set-up – than other costly commercially-available tools, giving equally reliable results. Validity and accuracy of the proposed tool have been verified through the design of 3rd, 5th, and 7th order coupled-line filters and comparative analysis between results obtained from the proposed approach and the high-frequency structure simulator. A remarkable 99% time reduction in the analysis is recorded in the case of 7th order filter using the proposed tool, for almost identical results to HFSS. Therefore, it can be confidently claimed that the proposed technique can be used as a reliable alternative to existing complex, costly, processor-intensive CAD tools.


Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 204
Author(s):  
Igor Siedlecki ◽  
Michał Gorczak ◽  
Alicja Okrasińska ◽  
Marta Wrzosek

Studies on carton nesting ants and domatia−dwelling ants have shown that ant–fungi interactions may be much more common and widespread than previously thought. Until now, studies focused predominantly on parasitic and mutualistic fungi–ant interactions occurring mostly in the tropics, neglecting less−obvious interactions involving the fungi common in ants’ surroundings in temperate climates. In our study, we characterized the mycobiota of the surroundings of Formica polyctena ants by identifying nearly 600 fungal colonies that were isolated externally from the bodies of F. polyctena workers. The ants were collected from mounds found in northern and central Poland. Isolated fungi were assigned to 20 genera via molecular identification (ITS rDNA barcoding). Among these, Penicillium strains were the most frequent, belonging to eight different taxonomic sections. Other common and widespread members of Eurotiales, such as Aspergillus spp., were isolated very rarely. In our study, we managed to characterize the genera of fungi commonly present on F. polyctena workers. Our results suggest that Penicillium, Trichoderma, Mucor, Schwanniomyces and Entomortierella are commonly present in F. polyctena surroundings. Additionally, the high diversity and high frequency of Penicillium colonies isolated from ants in this study suggest that representatives of this genus may be adapted to survive in ant nests environment better than the other fungal groups, or that they are preferentially sustained by the insects in nests.


Genetics ◽  
2003 ◽  
Vol 163 (4) ◽  
pp. 1337-1356 ◽  
Author(s):  
Adelaide T C Carpenter

Abstract The meiotic phenotypes of two mutant alleles of the mei-W68 gene, 1 and L1, were studied by genetics and by serial-section electron microscopy. Despite no or reduced exchange, both mutant alleles have normal synaptonemal complex. However, neither has any early recombination nodules; instead, both exhibit high numbers of very long (up to 2 μm) structures here named “noodles.” These are hypothesized to be formed by the unchecked extension of identical but much shorter structures ephemerally seen in wild type, which may be precursors of early recombination nodules. Although the mei-W68L1 allele is identical to the mei-W681 allele in both the absence of early recombination nodules and a high frequency of noodles (i.e., it is amorphic for the noodle phene), it is hypomorphic in its effects on exchange and late recombination nodules. The differential effects of this allele on early and late recombination nodules are consistent with the hypothesis that Drosophila females have two separate recombination pathways—one for simple gene conversion, the other for exchange.


Genes ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 30
Author(s):  
Perrine Pégorier ◽  
Morgane Bertignac ◽  
Viviane Nguefack Ngoune ◽  
Géraldine Folch ◽  
Joumana Jabado-Michaloud ◽  
...  

The adaptive immune response provides the vertebrate immune system with the ability to recognize and remember specific pathogens to generate immunity, and mount stronger attacks each time the pathogen is encountered. T cell receptors are the antigen receptors of the adaptive immune response expressed by T cells, which specifically recognize processed antigens, presented as peptides by the highly polymorphic major histocompatibility (MH) proteins. T cell receptors (TR) are divided into two groups, αβ and γδ, which express distinct TR containing either α and β, or γ and δ chains, respectively. The TRα locus (TRA) and TRδ locus (TRD) of bovine (Bos taurus) and the sheep (Ovis aries) have recently been described and annotated by IMGT® biocurators. The aim of the present study is to present the results of the biocuration and to compare the genes of the TRA/TRD loci among these ruminant species based on the Homo sapiens repertoire. The comparative analysis shows similarities but also differences, including the fact that these two species have a TRA/TRD locus about three times larger than that of humans and therefore have many more genes which may demonstrate duplications and/or deletions during evolution.


2021 ◽  
pp. 016344372110227
Author(s):  
Yingzi Wang ◽  
Thoralf Klein

This paper examines the changes and continuities in TV representations of Chinese Communist Party’s revolutionary history and interprets them within the broader context of China’s political, economic and cultural transformations since the 1990s. Drawing on a comparative analysis of three state-sponsored TV dramas produced between the late 1990s and mid-2010s, it traces how the state-sanctioned revolutionary narratives have changed over time in response to the Party’s propaganda imperatives on the one hand, and to the market-oriented production environment on the other. The paper argues that while recent TV productions in the new century have made increasing concessions to audience taste by adopting visually stimulating depictions and introducing fictional characters as points of identification for the audience, the revolutionary narratives were still aligned with the Party’s propaganda agenda at different times. This shows the ongoing competition between ideological and commercial interests in Chinese TV production during the era of market reforms.


Genetics ◽  
2001 ◽  
Vol 157 (3) ◽  
pp. 1387-1395 ◽  
Author(s):  
Sudhir Kumar ◽  
Sudhindra R Gadagkar ◽  
Alan Filipski ◽  
Xun Gu

AbstractGenomic divergence between species can be quantified in terms of the number of chromosomal rearrangements that have occurred in the respective genomes following their divergence from a common ancestor. These rearrangements disrupt the structural similarity between genomes, with each rearrangement producing additional, albeit shorter, conserved segments. Here we propose a simple statistical approach on the basis of the distribution of the number of markers in contiguous sets of autosomal markers (CSAMs) to estimate the number of conserved segments. CSAM identification requires information on the relative locations of orthologous markers in one genome and only the chromosome number on which each marker resides in the other genome. We propose a simple mathematical model that can account for the effect of the nonuniformity of the breakpoints and markers on the observed distribution of the number of markers in different conserved segments. Computer simulations show that the number of CSAMs increases linearly with the number of chromosomal rearrangements under a variety of conditions. Using the CSAM approach, the estimate of the number of conserved segments between human and mouse genomes is 529 ± 84, with a mean conserved segment length of 2.8 cM. This length is <40% of that currently accepted for human and mouse genomes. This means that the mouse and human genomes have diverged at a rate of ∼1.15 rearrangements per million years. By contrast, mouse and rat are diverging at a rate of only ∼0.74 rearrangements per million years.


2021 ◽  
Vol 11 (2) ◽  
pp. 726
Author(s):  
Xiaohan Xiang ◽  
Yoji Yamada ◽  
Yasuhiro Akiyama ◽  
Ziliang Tao ◽  
Naoki Kudo

Safety standard requirements must be implemented for lumbar support robots, which are mainly used for preventing low back pain (LBP) in caregivers. Usually, simulations are used to mimic actions that are not allowed for a real person. However, a comprehensive validation of a simulator in dynamic conditions has not been conducted. In this study, an ergonomic simulator is validated through forward flexion invasive experiments. The correspondence between the simulated and experimental compressive force (CF), as well as the CF obtained using two existing models about the unified angle, is investigated. The results show that the CF error between the measurements and the simulator at a flexion angle of 30∘ is 11.8% and is lower than those obtained for the other two models (16.8% and 20.6%). Linear regression shows that the invasive data and estimated CF are close (slope = 1) in Merryweather’s model and CF simulator but not for Potvin’s model. We evaluate the precision of the simulator by using intraclass correlation coefficient method. Merryweather’s model is moderately consistent with invasive measurements, with R–0.685 and 0.627 at 0 and 30∘, while the CF simulator shows good consistency with Merryweather’s model with R–0.879 and 0836 at 0 and 30∘.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bobby Lim-Ho Kong ◽  
Hyun-Seung Park ◽  
Tai-Wai David Lau ◽  
Zhixiu Lin ◽  
Tae-Jin Yang ◽  
...  

AbstractIlex is a monogeneric plant group (containing approximately 600 species) in the Aquifoliaceae family and one of the most commonly used medicinal herbs. However, its taxonomy and phylogenetic relationships at the species level are debatable. Herein, we obtained the complete chloroplast genomes of all 19 Ilex types that are native to Hong Kong. The genomes are conserved in structure, gene content and arrangement. The chloroplast genomes range in size from 157,119 bp in Ilex graciliflora to 158,020 bp in Ilex kwangtungensis. All these genomes contain 125 genes, of which 88 are protein-coding and 37 are tRNA genes. Four highly varied sequences (rps16-trnQ, rpl32-trnL, ndhD-psaC and ycf1) were found. The number of repeats in the Ilex genomes is mostly conserved, but the number of repeating motifs varies. The phylogenetic relationship among the 19 Ilex genomes, together with eight other available genomes in other studies, was investigated. Most of the species could be correctly assigned to the section or even series level, consistent with previous taxonomy, except Ilex rotunda var. microcarpa, Ilex asprella var. tapuensis and Ilex chapaensis. These species were reclassified; I. rotunda was placed in the section Micrococca, while the other two were grouped with the section Pseudoaquifolium. These studies provide a better understanding of Ilex phylogeny and refine its classification.


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