84 research outputs found

    Analyzing the PVCs Documents: A Multimodal Rate-based Approach to Understand Community’s Goals and Values

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    A significant amount of modern professional communication takes place in the so-called Virtual Communities of Practice or Professional Virtual Communities (PVCs): social systems of individuals who use Information Technologies to mediate their relationships and facilitate knowledge exchange and generation. In current research we analyze one of the biggest Russian IT-PVCs, Habrahabr.ru. The community’s official goal is connecting the IT-specialists; communication takes form of users articles and comments; users can rate the articles, the comments and the other users themselves. Using the number of SNA instruments, community’s metadata, linguistics statistics and discourse analysis we show the structure of the community, main topics within the professional field, and find the core ideas and values which “paste together” the communities members

    Cross-Polarization OCT for In Vivo Diagnostics and Prediction of Bladder Cancer

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    This chapter contains three parts covering recent efforts to increase the accuracy of optical coherence tomography (OCT) differential diagnostics of bladder pathologies. The first part compares the diagnostic efficacy of traditional OCT and cross-polarization OCT (CP OCT); CP OCT and fluorescence cystoscopy (FC) for detecting flat lesions in the bladder at the early stages of cancer. The second part contains a report on achievements in application of CP OCT for detection of recurrent carcinoma in the scar area that is a hardly distinguishable form of bladder cancer using an optimized CP OCT image analysis. The third part of the chapter reviews the results on CP OCT usage for in vivo diagnosis of the bladder cancer after radiation therapy of cervical cancer

    The impact of Ty3-gypsy group LTR retrotransposons Fatima on B-genome specificity of polyploid wheats

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    <p>Abstract</p> <p>Background</p> <p>Transposable elements (TEs) are a rapidly evolving fraction of the eukaryotic genomes and the main contributors to genome plasticity and divergence. Recently, occupation of the A- and D-genomes of allopolyploid wheat by specific TE families was demonstrated. Here, we investigated the impact of the well-represented family of <it>gypsy </it>LTR-retrotransposons, <it>Fatima</it>, on B-genome divergence of allopolyploid wheat using the fluorescent <it>in situ </it>hybridisation (FISH) method and phylogenetic analysis.</p> <p>Results</p> <p>FISH analysis of a BAC clone (BAC_2383A24) initially screened with Spelt1 repeats demonstrated its predominant localisation to chromosomes of the B-genome and its putative diploid progenitor <it>Aegilops speltoides </it>in hexaploid (genomic formula, BBAADD) and tetraploid (genomic formula, BBAA) wheats as well as their diploid progenitors. Analysis of the complete BAC_2383A24 nucleotide sequence (113 605 bp) demonstrated that it contains 55.6% TEs, 0.9% subtelomeric tandem repeats (Spelt1), and five genes. LTR retrotransposons are predominant, representing 50.7% of the total nucleotide sequence. Three elements of the <it>gypsy </it>LTR retrotransposon family <it>Fatima </it>make up 47.2% of all the LTR retrotransposons in this BAC. <it>In situ </it>hybridisation of the <it>Fatima</it>_2383A24-3 subclone suggests that individual representatives of the <it>Fatima </it>family contribute to the majority of the B-genome specific FISH pattern for BAC_2383A24. Phylogenetic analysis of various <it>Fatima </it>elements available from databases in combination with the data on their insertion dates demonstrated that the <it>Fatima </it>elements fall into several groups. One of these groups, containing <it>Fatima</it>_2383A24-3, is more specific to the B-genome and proliferated around 0.5-2.5 MYA, prior to allopolyploid wheat formation.</p> <p>Conclusion</p> <p>The B-genome specificity of the <it>gypsy</it>-like <it>Fatima</it>, as determined by FISH, is explained to a great degree by the appearance of a genome-specific element within this family for <it>Ae. speltoides</it>. Moreover, its proliferation mainly occurred in this diploid species before it entered into allopolyploidy.</p> <p>Most likely, this scenario of emergence and proliferation of the genome-specific variants of retroelements, mainly in the diploid species, is characteristic of the evolution of all three genomes of hexaploid wheat.</p

    Isolation and sequence analysis of the wheat B genome subtelomeric DNA

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    <p>Abstract</p> <p>Background</p> <p>Telomeric and subtelomeric regions are essential for genome stability and regular chromosome replication. In this work, we have characterized the wheat BAC (bacterial artificial chromosome) clones containing Spelt1 and Spelt52 sequences, which belong to the subtelomeric repeats of the B/G genomes of wheats and <it>Aegilops </it>species from the section <it>Sitopsis</it>.</p> <p>Results</p> <p>The BAC library from <it>Triticum aestivum </it>cv. Renan was screened using Spelt1 and Spelt52 as probes. Nine positive clones were isolated; of them, clone 2050O8 was localized mainly to the distal parts of wheat chromosomes by <it>in situ </it>hybridization. The distribution of the other clones indicated the presence of different types of repetitive sequences in BACs. Use of different approaches allowed us to prove that seven of the nine isolated clones belonged to the subtelomeric chromosomal regions. Clone 2050O8 was sequenced and its sequence of 119 737 bp was annotated. It is composed of 33% transposable elements (TEs), 8.2% Spelt52 (namely, the subfamily Spelt52.2) and five non-TE-related genes. DNA transposons are predominant, making up 24.6% of the entire BAC clone, whereas retroelements account for 8.4% of the clone length. The full-length CACTA transposon <it>Caspar </it>covers 11 666 bp, encoding a transposase and CTG-2 proteins, and this transposon accounts for 40% of the DNA transposons. The <it>in situ </it>hybridization data for 2050O8 derived subclones in combination with the BLAST search against wheat mapped ESTs (expressed sequence tags) suggest that clone 2050O8 is located in the terminal bin 4BL-10 (0.95-1.0). Additionally, four of the predicted 2050O8 genes showed significant homology to four putative orthologous rice genes in the distal part of rice chromosome 3S and confirm the synteny to wheat 4BL.</p> <p>Conclusion</p> <p>Satellite DNA sequences from the subtelomeric regions of diploid wheat progenitor can be used for selecting the BAC clones from the corresponding regions of hexaploid wheat chromosomes. It has been demonstrated for the first time that Spelt52 sequences were involved in the evolution of terminal regions of common wheat chromosomes. Our research provides new insights into the microcollinearity in the terminal regions of wheat chromosomes 4BL and rice chromosome 3S.</p

    Economic Migration in Central Siberia and Ethnic Conflict Risks (Based on Krasnoyarsk Krai Analysis)

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    Migration, be it free or forced, is an essential prerequisite of the dynamic development of many territories, Krasnoyarsk Krai inclusive. The territory of the region is irregularly and poorly populated: 84% of inhabitants are concentrated in the south of the region, in the territory comprising only 10% of the regional territory. Under the circumstances Krasnoyarsk Krai needs an increased flow of migrants for the participation in economic development of unpopulated areas of Krai. But on the other hand, economic need in migrants becomes the reason of the ethnic conflicts risks increase in Central Siberia through creation of various negative myths on migrants. The experts report an increase in social tension between migrants and host parties in the Siberian regions of the Russian Federation. The interrelations inside the social medium and cultural contacts are in many respects determinant for the economic development of the region because the main actors of the economics are people. Keywords: economic migration, tolerance index, Siberia, Krasnoyarsk Krai JEL Classifications: D8, R1, Z

    The Influence of Neurotrophic Factors BDNF and GDNF Overexpression on the Functional State of Mice and Their Adaptation to Audiogenic Seizures.

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    peer reviewedThe high prevalence of diagnosed cases of severe neurological disorders, a significant proportion of which are epilepsy, contributes to a high level of mortality and disability in the population. Neurotrophic factors BDNF and GNDF are considered promising agents aimed at increasing the central nervous system's adaptive potential for the development of the epileptiform activity. Despite the pronounced neuroprotective and anticonvulsant potential, an appropriate way to stimulate these endogenous signaling molecules with minimal risk of side effects remains an open question. Herein, we assessed the safety of gene therapy using original adeno-associated viral constructs carrying the genes of neurotrophic factors BDNF and GDNF in the early postnatal period of development of experimental animals. The intraventricular injection of AAV-Syn-BDNF-eGFP and AAV-Syn-GDNF-eGFP viral constructs into newborn mice was found to provide persistent overexpression of target genes in the hippocampus and cerebral cortex in vivo for four weeks after injection. The application of viral constructs has a multidirectional effect on the weight and body length characteristics of mice in the early postnatal period; however, it ensures the animals' resistance to the development of seizure activity under audiogenic stimulation in the late postnatal period and preserves basic behavioral reactions, emotional status, as well as the mnestic and cognitive abilities of mice after simulated stress. Our results demonstrated the safety of using the AAV-Syn-BDNF-eGFP and AAV-Syn-GDNF-eGFP viral constructs in vivo, which indicates the expediency of further testing the constructs as therapeutic anticonvulsants

    Shifting the limits in wheat research and breeding using a fully annotated reference genome

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    Introduction: Wheat (Triticum aestivum L.) is the most widely cultivated crop on Earth, contributing about a fifth of the total calories consumed by humans. Consequently, wheat yields and production affect the global economy, and failed harvests can lead to social unrest. Breeders continuously strive to develop improved varieties by fine-tuning genetically complex yield and end-use quality parameters while maintaining stable yields and adapting the crop to regionally specific biotic and abiotic stresses. Rationale: Breeding efforts are limited by insufficient knowledge and understanding of wheat biology and the molecular basis of central agronomic traits. To meet the demands of human population growth, there is an urgent need for wheat research and breeding to accelerate genetic gain as well as to increase and protect wheat yield and quality traits. In other plant and animal species, access to a fully annotated and ordered genome sequence, including regulatory sequences and genome-diversity information, has promoted the development of systematic and more time-efficient approaches for the selection and understanding of important traits. Wheat has lagged behind, primarily owing to the challenges of assembling a genome that is more than five times as large as the human genome, polyploid, and complex, containing more than 85% repetitive DNA. To provide a foundation for improvement through molecular breeding, in 2005, the International Wheat Genome Sequencing Consortium set out to deliver a high-quality annotated reference genome sequence of bread wheat. Results: An annotated reference sequence representing the hexaploid bread wheat genome in the form of 21 chromosome-like sequence assemblies has now been delivered, giving access to 107,891 high-confidence genes, including their genomic context of regulatory sequences. This assembly enabled the discovery of tissue- and developmental stage–related gene coexpression networks using a transcriptome atlas representing all stages of wheat development. The dynamics of change in complex gene families involved in environmental adaptation and end-use quality were revealed at subgenome resolution and contextualized to known agronomic single-gene or quantitative trait loci. Aspects of the future value of the annotated assembly for molecular breeding and research were exemplarily illustrated by resolving the genetic basis of a quantitative trait locus conferring resistance to abiotic stress and insect damage as well as by serving as the basis for genome editing of the flowering-time trait. Conclusion: This annotated reference sequence of wheat is a resource that can now drive disruptive innovation in wheat improvement, as this community resource establishes the foundation for accelerating wheat research and application through improved understanding of wheat biology and genomics-assisted breeding. Importantly, the bioinformatics capacity developed for model-organism genomes will facilitate a better understanding of the wheat genome as a result of the high-quality chromosome-based genome assembly. By necessity, breeders work with the genome at the whole chromosome level, as each new cross involves the modification of genome-wide gene networks that control the expression of complex traits such as yield. With the annotated and ordered reference genome sequence in place, researchers and breeders can now easily access sequence-level information to precisely define the necessary changes in the genomes for breeding programs. This will be realized through the implementation of new DNA marker platforms and targeted breeding technologies, including genome editing
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