60 research outputs found
Annual of Sofia University „St. Kliment Ohridski“ Faculty of Philosophy. Psychology. Volume 105
Full text linkАвтори в Т. 105: Ирина Зиновиева; Момчил Киряков;Анелия Петрова, Дамяна Иванова; Йоана Янкулова; Даниел Петров;Весела Кръстева-Симеонова; Антония Димитрова; Люба Маринова; Петър ВълковAuthors: Irina Zinovieva, Momchil Kiryakov, Aneliya Petrova, Damyana Ivanova, Yoana Yankulova, Daniel Petrov, Vesela Krasteva-Simeonova, Antonia Dimitrova, Lyuba Marinova, Petar Valko
Robustness and plasticity of epithelial cell state in development and malignancy
Full text linkA better understanding of the molecular mechanisms that control pluripotency,
differentiation and epithelial phenotypical plasticity is crucial for the development of
the current knowledge in many general processes such as cell identity maintenance
and cell fate decision-making.
Embryonic stem cells (ESC) pluripotency maintenance and differentiation are of key
importance to the embryonic development, as well as to the progress in stem cells
technologies. The role of miR-290-295 cluster members in preserving the pluripotent
state and differentiation potential of mouse ESC is well established. Nevertheless, the
precise list of targets translating the microRNAs functionality is incomplete. In our
study we, firstly, identified and validated miR-290 targets with high confidence. We
further confirmed the expression variation of IRF2 in response to miRNAs’ depletion
in ESC. Moreover, we revisited the involvement of nuclear factor kappa-B (NF-kB)
pathway in the miRNA-dependent regulation in mESCs. Hence, our results provided
new understanding of the role and mechanistic of miR-290-295 microRNAs
involvement in ESC pluripotency and differentiation.
In a similar fashion to ESC pluripotency and differentiation mechanisms, a globalanalysis-approach that compares and combines data from different epithelial to
mesenchymal transition (EMT) models enabled us to construct a more detailed
network of regulatory entities implicated in epithelial plasticity. The maintenance and
plasticity of the epithelial cell phenotype are important events not only during normal
embryonic development, but also to cancer progression and metastasis formation.
Comparing this network between mouse and human, we identified a new transcription
factor (TF) motif TFAP2A/C that is consistently involved in EMT. When applying
the NMuMG cellular model of TGFβ-induced EMT, we found that the predicted
activity of the TFAP2A/C is inversely correlated to the Tfap2a mRNA expression
during the process. We have confirmed that TFAP2A directly binds to the promoter
of Zeb2, a TF central to EMT. Thus, it regulates the expression of this gene.
Furthermore, the TFAP2A overexpression in NMuMG cells modulates the cells’
epithelial phenotype and induces changes in cell adhesion and morphology. This
overexpression was followed by increased mRNA levels of EMT master regulator
TFs, together with an elevated expression of genes involved in cellular adhesion.
Therefore, we identified a potentially new role of TFAP2A transcription factor, which
suggests that elements of its regulatory function during neural crest development
might operate in mechanisms controlling epithelial plasticity in normal breast and
tumor tissues.
Overall, we characterized another facet of microRNAs’ function in pluripotency and
differentiation in ESC, as well as a new aspect of the implication of TFAP2A in
epithelial cell state integrity and plasticity. Therefore we contributed to expanding our
insight of how are regulated at molecular level the cell identity homeostasis and the
unfolding of cellular phenotypical plasticity
Efficient and proven verification of unreliable hardware executions of classic algorithms
No full textThesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2015.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis.Includes bibliographical references (pages 59-61).Lowering voltage and frequency guardbands of CPU, DRAM, cache, or interconnect lowers power and latency, but increases the risk of silent data corruptions in even formally verified hardware and software. Researchers have been developing systems that use unreliable hardware, combined with software checkers executed on reliable hardware, to gain high performance with no risk. Deterministic checkers for many important algorithms are asymptotically and practically more efficient than the original problem solvers, e.g. for systems of linear equations, satisfiability, linear programming, sorting, 3SUM, graph matching and others. Writing a correct checker is hard, since often intricate corner cases get overlooked. Our system, SOUNDCHECK, helps reduce burden on programmers by automatically proving soundness and completeness of checkers with bounded verification in the Sketch program synthesis language. Verified checkers are emitted as efficient C++ code and shown to have low overhead which results in a net performance improvement with no risk.by Yoana G. Gyurova.M. Eng
The Effect of Using Cooperative Integrated Reading Composition (CIRC) Technique on Students’ Reading Comprehension of Recount Text at MAN 1 Pekanbaru
Full text linkABSTRACT
Yoana Fidela (2020): The Effect of Using Cooperative Integrated Reading Composition (CIRC) Technique on Students’ Reading Comprehension of Recount Text at MAN 1 Pekanbaru
Based on the researcher's preliminary study, it was found that, some students still have problems in English, especially reading comprehension in the recount text. Therefore the author is interested in conducting research on the problem. This research was conducted at MAN 1 Pekanbaru. The subjects of this study were tenth graders at MAN 1 Pekanbaru and the object of this study was the Effect of Cooperative Integrated Reading and Composition (CIRC) Against Understanding Recount Text Reading of tenth grade students at MAN 1 Pekanbaru. The type of research is Quasi-experiment. The population of this study was all tenth grade students. The total population is 326 students. Researchers took samples of class X MIA 1 consisting of 38 students as an experimental group and class X MIA 2 consisting of 36 students as a control group. So, the number of samples from the two classes is 74 students. For the data analysis, researchers used Independent sample T-test through SPSS. After the data were analyzed, researchers found the average score of students’ reading comprehension of recount text taught without using CIRC technique at the tenth grade of MAN 1 Pekanbaru were 65.83 in pre-test and 82.08 in post test, the average score of students’ reading comprehension of recount text taught by using CIRC technique at the tenth grade of MAN 1 Pekanbaru were 67.5 in pre-test and 88.82 in post test and there is significant effect of using CIRC technique on students’ reading comprehension of recount text at the tenth grade of MAN 1 Pekanbaru with score 15.6%
Turismo experiencial: una revisión de la literatura
Full text link[spa] El presente trabajo de fin de grado trata de analizar la importancia y la
evolución del Turismo Experiencial, llevando a cabo una breve revisión de la
literatura.
El objetivo de este estudio es, en primer lugar, analizar el concepto general de
turismo y los factores que influyen en la evolución del turismo; acto seguido,
examinar el concepto de turismo experiencial y los antecedentes que han
favorecido su desarrollo; en tercer lugar, describir su evolución desde la
economía de servicios a la economía de experiencias; y finalmente, a través de
una revisión de la literatura, detallar la importancia del turismo experiencial y
los impactos que ha generado.[eng] The present end-of-degree project tries to analyze the importance and the
evolution of Experiential Tourism, carrying out a short literatura review.
The objective of this study is, first, to analyze the general concept of tourism
and the factors that influence the evolution of tourism; act followed, to examine
the concept of experiential tourism and the antecedents that have favored its
development; third, to describe its evolution from the economy of services to the
economy of experiences; and finally, through a review of the literature, to detail
the importance of experiential tourism and the impacts it has generated
Transformación turística del municipio de Calvià. Gestión del enfrentamiento entre lo nuevo y lo viejo
Full text link[spa] A lo largo de este trabajo se expondrán diferentes temas relacionados con la Reconversión del destino turístico maduro del municipio de Calvià, en las Islas Baleares. Se iniciará con la introducción del término de zona madura a través de un ejemplo de un territorio muy conocido que ha sufrido el mismo proceso, para centrarse más adelante,en la región objeto de estudio analizando sus características y evolución turística a lo largo de los años hasta llegar a la fase actual de madurez. A partir de allí, se analizará la forma de llevar a cabo dicha transformación necesaria y cuáles han sido las dificultades del proceso. Para conocer más a fondo sobre el tema, se contará con los conocimientos y opiniones de tres personas que están directamente envueltos en el proyecto y observándolo de primera mano.[eng] Throughout this work, will be explained different topics related to the restructuring of the mature tourist destination of the municipality of Calvià, in the Balearic Islands. It begins with the introduction of the term of mature area through an example of a well-known territory that has undergone the same process, and later focuses on the objective region study, analyzing its characteristics and touristic evolution over the years until reaching the current stage of maturity. From this point, it will be analyzed how to carry out the necessary change and which were the difficulties of the process.The knowledge and opinions of three people who are directly involved in the project and have first-hand observations have been used for the study in order to learn more about the subject
Biochemical and structural analyses of TBL1: insights into the function of a transcriptional regulator
No full textThe mechanism controlling the switch between gene activation and repression is critically important for understanding the process of transcriptional regulation. Gene expression is highly controlled through a dynamic exchange between co-activators and co-repressors from DNA bound transcription factors. TBL1 is an essential multi-domain scaffolding protein that appears to mediate the switch between transcriptional activation and repression of β-catenin and nuclear hormone receptors (NHRs). The mechanism of TBL1 as a transcriptional regulator has been the main focus of this dissertation.
The role of TBL1 was first investigated in the context of the SCF(TBL1) complex in the poly-ubiquitination and proteasomal degradation of β-catenin under UV-induced genotoxic stress. Over-expression and purification protocols were developed for each of the SCF(TBL1) proteins, enabling a systematic analysis of β-catenin ubiquitination using an in vitro ubiquitination assay. This study revealed that Siah-1 alone was able to poly-ubiquitinate β-catenin. Moreover, TBL1 was found to protect β-catenin from Siah-1 ubiquitination in vitro and from Siah-1-targeted proteasomal degradation in cells. Both Siah-1 and TBL1 bind to the armadillo repeat domain of β-catenin, suggesting poly-ubiquitination of β-catenin is regulated by competition between Siah-1 and TBL1.
To gain insight into the function of TBL1 within multi-protein complexes that regulate the transcriptional activity of β-catenin and NHRs, this work pursued the structural and biochemical characterization of TBL1. Expression, purification and analysis of full length TBL1 and different domain constructs revealed that it forms a stable tetramer through the N-terminal LisH domain. The structural architecture of full length TBL1 and the spatial organization of the domains were characterized by small angle x-ray scattering (SAXS) and analytical ultracentrifugation (AUC). An ab initio model of TBL1 was generated, revealing an extended anti-parallel dimer of dimers. The structure of TBL1 has a large surface area that can accommodate multiple binding partners, suggesting a role for TBL1 tetramerization in facilitating the formation of multi-protein assemblies. TBL1 mutants that form only dimers were designed and validated to enable future functional studies of the mechanism of TBL1 in regulating the transcriptional activity of β-catenin and NHRs
Biochemical and structural analyses of TBL1: insights into the function of a transcriptional regulator
Full text linkModelling the impact of cyber attacks on the traffic control centre of an urban automobile transport system by means of enhanced cybersecurity
Full text linkThis paper aims to show the major role means of protection play for strengthening the cybersecurity of critical transport infrastructure by using the advanced method of simulation modelling. The simulation model of a Traffic Control Centre (TTC) of an urban Automobile Transport System (ATS) is created by the author in the Riverbed Modeler Academic Edition 17.5 computer networks simulation system and is exposed to the impact of a Denial-of-Service attack. In addition, logical conclusions have been made on the basis of the experimental results obtained and evaluated by comparative analysis with results from analogous previous studies
A methodology for empirical research and analysis in the field of cybersecurity
Full text linkThis article is considered to be a continuation of a publication by the author devoted to an algorithm for steganographic embedding of encrypted files in raster images (Yearbook Telecommunication, №9, 2022). The aim of this paper is proposing a methodology for empirical research and analysis on the field of cybersecurity which to contribute to various areas in cybersecurity. Its originality is expressed in the joint application of methods for research and analysis realized by various simulation environments for conducting experiments. This methodology has a specific structure as it is conditionally divided into two major parts depending on the type of the simulation process and software products used – a study of the direct impact of cyberattacks on communication networks by the method of the agent-based modelling and a study of potential steganography attacks using software for simulation of Artificial Neural Networks (ANNs) for the purposes of steganalysis
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