978 resultados para Stimulatory Cpg Motifs


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Wydział Neofilologii: Katedra Studiów Azjatyckich

Relevância:

10.00% 10.00%

Publicador:

Resumo:

One can say that our times are dominated by visual communication. Usually all day long we have been faced by various pictures, visual forms and symbols. According to the subject of the book 'Archaeology-Culture-Ideologies' I found it interesting to pay attention to the problem of visual representation, or better say visual symbols in nowadays communication and culture, their meaning and importance. From this point of view I would like to show the role of archaeologists who discover, interpret or even create some of them. The subject is not new of course, but the most often it is taken into consideration by the scholars who practice in social anthropology or philosophy and quite rarely it appear in studies of archaeologies, especially in Polish tradition. In my opinion the subject concerning visual symbols communication and archaeology arise several important questions that are also valid for the theme of book 'Archaeology-Culture-Ideologies'. The first is socio-cultural role of our discipline, next the danger of political and propaganda misuse of the results of archaeological research and then also commercialisation of the archaeological activities. The problem of visualisation and visual-communication can be the matter of various studies. In my paper from the beginning I would like to present the general view concerning visual symbols and figural motifs and the main ideas and approaches to study them from different humanistic perspectives. Then in my presentation I am going to discuss the question why in our culture the visual symbols and representations became so popular – compare to other ways of human expression, for example verbal symbol communication. I would like to see the problem in historical perspective as well. There are a lot of evidences, which support the statement about the power of visual symbols in history. In ancient times for example Horace in 'Ars Poetica' suggested that human mind usually is much more impressed by eyes than by ears. In my opinion that is quite often in human culture that visual impression is before mental one. Visual representations and symbols are very powerful, they can show and communicate various phenomena, they act immediately and quite often in easily way they can associate. So for archaeological research it could be very important to make some studies concerning the ancient symbols and general iconography and also it would be grateful to make some attempts for the study what kind of potential meaning could have visual symbols. In my paper I can only make some general statement about it. But the most important for the topic is reflection on prehistoric and ancient visual symbols and representation and their presence in contemporary culture. So after some general statements concerning the visual symbols examined from various perspectives finally I would like to point out with support of some examples how ancient and prehistoric visual symbols and images are still used and captured by contemporary culture and what is or should be the role of archaeologists activity concerning this matter.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Głównym celem dysertacji jest interpretacja twórczości Bulanda al-Ḥaydarīego (iracki poeta kurdyjskiego pochodzenia (1926-1996)). Utwory Al-Ḥaydarīego zawierają w sobie charakterystyczne cechy współczesnego wiersza arabskiego. Opisują ponadto najważniejsze historyczne, społeczne i osobiste doświadczenia literackiego pokolenia tego poety, jak również innych członków społeczności arabskiej w okresie po II wojnie światowej. Praca doktorska składa się z dwóch części. Pierwszą część poprzedza krótki opis stanu badań nad liryką Al-Ḥaydarīego. W pierwszym jej rozdziale przedstawiono życiorys i biografię literacką poety oraz wyjaśniono pojęcia takie jak: ‘współczesna poezja arabska’, ‘wolna poezja’, ‘poemat prozą’ czy ‘ruch wolnej poezji’. Wspomniano również o głównych nurtach w poezji arabskiej w latach 50. i 60. XX w., jak również ukazano sposób, w jaki modernistyczni poeci postrzegali poezję. Natomiast w drugim rozdziale przedstawiono pokrótce charakterystyczne cechy (stylistyczne, składniowe i melodyczne) współczesnego wiersza arabskiego i zilustrowano je fragmentami utworów Al-Ḥaydarīego. Druga część dysertacji składa się z pięciu rozdziałów. W każdym z nich przedstawiono jeden lub kilka głównych motywów oraz ich różne warianty: w pierwszym rozdziale – motyw miłość, w drugim – motyw istnienia (życie i śmierć), w trzecim – motywy ojczyzny, obczyzny, zaangażowania społecznego twórcy i jego wyobcowania, w czwartym – motyw przestrzeni (np. dom, droga, raj, piekło) oraz w piątym – motyw czasu (przeszłość, teraźniejszość, przyszłość).

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Chapter is an attempt at reconstruction of the culminating moment of the first stage of the Polish reception of Shakespeare's "Hamlet". It has been entirely devoted to J. Słowacki's "Horsztyński". There is no doubt that "Horsztyński" should be viewed as the fullest and deepest interpretation of Shakespearean elements in the literary output of Juliusz Słowacki. Numerous citations and references to the works of the Elizabethan dramatist reach deeply into the structure of the world and human's life. Thanks to many adductions (citations) to Shakespeare, Słowacki approached the so much important problem for the Romantic period in Polish literature, namely the problem of individual tragedy of existence of the main character of a play and a clash with historical dilemmas of the community. The analysis of the text is aimed at showing all references to Shakespearean masterpiece with a particular emphasis on the hamletism of the charactwe of Szczęsny Kossakowski. The author describes the motif of betrayal, ever-present on different levels of the text structure, which in the most complete way describes the organisation of space between humans and their interaction in "Horsztyński". The author focuses his attention on detailed description and analysis of the recurrent themes frequently repeated in Szczęsny's statements, namely motifs of "man-harp", "man-actor in the theatre of the world", and "man-puppet", harlequin, clown. These motifs prove the sensibility of Szczęsny's to the theatrical aspect of the surrounding reality. The motif of darkness and of a blind man groping his way in the darkness so frequent in Szczęsny's statements can be interpreted as a manifestation of utter lack of hope and the feeling of uselessness of one's existence in the world.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Wydział Biologii: Instytut Biologii Molekularnej i Biotechnologii

Relevância:

10.00% 10.00%

Publicador:

Resumo:

BACKGROUND:Short (~5 nucleotides) interspersed repeats regulate several aspects of post-transcriptional gene expression. Previously we developed an algorithm (REPFIND) that assigns P-values to all repeated motifs in a given nucleic acid sequence and reliably identifies clusters of short CAC-containing motifs required for mRNA localization in Xenopus oocytes.DESCRIPTION:In order to facilitate the identification of genes possessing clusters of repeats that regulate post-transcriptional aspects of gene expression in mammalian genes, we used REPFIND to create a database of all repeated motifs in the 3' untranslated regions (UTR) of genes from the Mammalian Gene Collection (MGC). The MGC database includes seven vertebrate species: human, cow, rat, mouse and three non-mammalian vertebrate species. A web-based application was developed to search this database of repeated motifs to generate species-specific lists of genes containing specific classes of repeats in their 3'-UTRs. This computational tool is called 3'-UTR SIRF (Short Interspersed Repeat Finder), and it reveals that hundreds of human genes contain an abundance of short CAC-rich and CAG-rich repeats in their 3'-UTRs that are similar to those found in mRNAs localized to the neurites of neurons. We tested four candidate mRNAs for localization in rat hippocampal neurons by in situ hybridization. Our results show that two candidate CAC-rich (Syntaxin 1B and Tubulin beta4) and two candidate CAG-rich (Sec61alpha and Syntaxin 1A) mRNAs are localized to distal neurites, whereas two control mRNAs lacking repeated motifs in their 3'-UTR remain primarily in the cell body.CONCLUSION:Computational data generated with 3'-UTR SIRF indicate that hundreds of mammalian genes have an abundance of short CA-containing motifs that may direct mRNA localization in neurons. In situ hybridization shows that four candidate mRNAs are localized to distal neurites of cultured hippocampal neurons. These data suggest that short CA-containing motifs may be part of a widely utilized genetic code that regulates mRNA localization in vertebrate cells. The use of 3'-UTR SIRF to search for new classes of motifs that regulate other aspects of gene expression should yield important information in future studies addressing cis-regulatory information located in 3'-UTRs.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

1) A large body of behavioral data conceming animal and human gaits and gait transitions is simulated as emergent properties of a central pattern generator (CPG) model. The CPG model incorporates neurons obeying Hodgkin-Huxley type dynamics that interact via an on-center off-surround anatomy whose excitatory signals operate on a faster time scale than their inhibitory signals. A descending cornmand or arousal signal called a GO signal activates the gaits and controL their transitions. The GO signal and the CPG model are compared with neural data from globus pallidus and spinal cord, among other brain structures. 2) Data from human bimanual finger coordination tasks are simulated in which anti-phase oscillations at low frequencies spontaneously switch to in-phase oscillations at high frequencies, in-phase oscillations can be performed both at low and high frequencies, phase fluctuations occur at the anti-phase in-phase transition, and a "seagull effect" of larger errors occurs at intermediate phases. When driven by environmental patterns with intermediate phase relationships, the model's output exhibits a tendency to slip toward purely in-phase and anti-phase relationships as observed in humans subjects. 3) Quadruped vertebrate gaits, including the amble, the walk, all three pairwise gaits (trot, pace, and gallop) and the pronk are simulated. Rapid gait transitions are simulated in the order--walk, trot, pace, and gallop--that occurs in the cat, along with the observed increase in oscillation frequency. 4) Precise control of quadruped gait switching is achieved in the model by using GO-dependent modulation of the model's inhibitory interactions. This generates a different functional connectivity in a single CPG at different arousal levels. Such task-specific modulation of functional connectivity in neural pattern generators has been experimentally reported in invertebrates. Phase-dependent modulation of reflex gain has been observed in cats. A role for state-dependent modulation is herein predicted to occur in vertebrates for precise control of phase transitions from one gait to another. 5) The primary human gaits (the walk and the run) and elephant gaits (the amble and the walk) are sirnulated. Although these two gaits are qualitatively different, they both have the same limb order and may exhibit oscillation frequencies that overlap. The CPG model simulates the walk and the run by generating oscillations which exhibit the same phase relationships. but qualitatively different waveform shapes, at different GO signal levels. The fraction of each cycle that activity is above threshold quantitatively distinguishes the two gaits, much as the duty cycles of the feet are longer in the walk than in the run. 6) A key model properly concerns the ability of a single model CPG, that obeys a fixed set of opponent processing equations to generate both in-phase and anti-phase oscillations at different arousal levels. Phase transitions from either in-phase to anti-phase oscillations, or from anti-phase to in-phase oscillations, can occur in different parameter ranges, as the GO signal increases.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This thesis is a study of Konrad Bayer's dramatic texts. It has evolved out of various attempts to read those texts, some filed and some more successful. It does not claim to be authoritative or complete, since the nature of Bayer's texts, as will become clear in the course of the ensuing chapters, means that they resist such an interpretation. To accept this was an important prerequisite for the writing of this thesis, but a difficult one to fulfill because for the Bayer commentator it constitutes a certain acceptance of defeat even before one begins. Chapter 1 will begin by providing some introductory information about Konrad Bayer, including details of his life and his membership of the Wiener Gruppe, a formative phase in his development as a writer. It will also consider the historical and cultural climate of 1950s Austria that provided the backdrop for Bayer's literary work. The phenomenon of the Wiener Gruppe will then be examined against the background of preceding experimental movements, for the purpose of situating Bayer's work historically and artistically. The aim of this historical and artistic survey is to prepare for the confrontation with Bayer's texts that makes up the other chapters of the thesis. Chapter 2 will constitute a close textual study of one of Bayer's dramatic texts using criteria from the field of text linguistics. Such a study will offer an entry point into Bayer's texts and will supply material which will form the basis for the interpretative investigations of the chapters that follow it. Chapter 3 will consider the influence of language and the individual. In chapter 4 the figure of the Lion of Belfort, a recurring figure in Bayer's dramatic texts, is discussed. The final chapter of this thesis will examine the recurring motifs of violence and cannibalism and will consider them in terms of the findings of preceding chapters.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This thesis is focused on the synthesis and solid state analysis of carbohydrate derivatives, including many novel compounds. Although the synthetic chemistry surrounding carbohydrates is well established in the literature, the crystal chemistry of carbohydrates is less well studied. Therefore this research aims to improve understanding of the solid state properties of carbohydrate derivatives through gaining more information on their supramolecular bonding. Chapter One focuses on an introduction to the solid state of organic compounds, with a background to crystallisation, including issues that can arise during crystal growth. Chapter Two is based on glucopyranuronate derivatives which are understudied in terms of their solid state forms. This chapter reports on the formation of novel glucuronamides and utilising the functionality of the amide bond for crystallisation. TEMPO oxidation was completed to form glucopyranuronates by oxidation of the primary alcohol groups of glucosides to the carboxylic acid derivatives, to increase functionality for enhanced crystal growth. Chapter Three reports on the synthesis of glucopyranoside derivatives by O-glycosylation reactions and displays crystal structures, including a number of previously unsolved acetate protected and deprotected crystal structures. More complex glycoside derivatives were also researched in an aim to study the resultant supramolecular motifs. Chapter Four contains the synthesis of aryl cellobioside derivatives including the novel crystal structures that were solved for the acetate protected and deprotected compounds. Research was carried out to determine if 1-deoxycellodextrins could act as putative isostructures for cellulose. Our research displays the presence of isostructural references with 1-deoxycellotriose shown to be similar to cellulose III11, 1-deoxycellotetraose correlates with cellulose IV11 and 1-deoxycellopentose shows isostructurality similar to that of cellulose II. Chapter Five contains the full experimental details and spectral characterisation of all novel compounds synthesised in this project and relevant crystallographic information.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This dissertation examines medieval literary accounts of visions of the afterlife with an origin or provenance in Ireland from the perspective of genre, analysing their structural and literary characteristics both synchronically and diachronically. To this end, I have developed a new typology of medieval vision literature. I address the question in what manner the internationally attested genre of vision literature is adapted and developed in an Irish literary milieu. I explore this central research question through an interrogation of the typological unity of the key texts, both in formal arrangement and in the eschatological themes they express. My analysis of the structure and rhetoric of these narratives reveals the primary role of identity strategies, question-and-answer patterns and exhortation for their narrative cohesion and didactic function. In addition, I was able to make a formal distinction at text-level between the adaptation of the genre as an autonomous unit and the adaptation of thematic motifs as topoi. This further enabled me to nuance the distribution of characteristic features in the genre. My analysis of the spatial and temporal aspects of the eschatological journey confirms a preoccupation with personal eschatology. It reveals a close connection between the development of the aspects of graded access and trial in the genre and a growing awareness of an interim state of the soul after death. Finally, my dissertation provides new editions, translations and analyses of primary sources. My research breaks new ground in the hitherto underexplored area of genre adaptation in Ireland. In addition, it contributes significantly to our understanding of the nature of vision literature both in an Irish and a European context, and to our knowledge of the transmission of eschatological thought in the Latin West. Discusses the visions of: Laisrén, Fursa, Adomnán, Lóchán, Tnugdal, Owein and Visio Sancti Pauli Redactions VI and XI.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Cytokine-driven signalling shapes immune homeostasis and guides inflammatory responses mainly through induction of specific gene expression programmes both within and outside the immune cell compartment. These transcriptional outputs are often amplified via cytokine synergy, which sets a stimulatory threshold that safeguards from exacerbated inflammation and immunopathology. In this study, we investigated the molecular mechanisms underpinning synergy between two pivotal Th1 cytokines, IFN-γ and TNF-α, in human intestinal epithelial cells. These two proinflammatory mediators induce a unique state of signalling and transcriptional synergy implicated in processes such as antiviral and antitumour immunity, intestinal barrier and pancreatic β-cell dysfunction. Since its discovery more than 30 years ago, this biological phenomenon remains, however, only partially defined. Here, using a functional genomics approach including RNAi perturbation screens and small-molecule inhibitors, we identified two new regulators of IFN-γ/TNF-α-induced chemokine and antiviral gene and protein expression, a Bcl-2 protein BCL-G and a histone demethylase UTX. We also discovered that IFN-γ/TNF-α synergise to trigger a coordinated shutdown of major receptor tyrosine kinases expression in colon cancer cells. Together, these findings extend our current understanding of how IFN-γ/TNF-α synergy elicits qualitatively and quantitatively distinct outputs in the intestinal epithelium. Given the well-documented role of this synergistic state in immunopathology of various disorders, our results may help to inform the identification of high quality and biologically relevant druggable targets for diseases characterised by an IFN-γ/TNF-α high immune signature

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Phages belonging to the 936 group represent one of the most prevalent and frequently isolated phages in dairy fermentation processes using Lactococcus lactis as the primary starter culture. In recent years extensive research has been carried out to characterise this phage group at a genomic level in an effort to understand how the 936 group phages dominate this particular niche and cause regular problems during large scale milk fermentations. This thesis describes a large scale screening of industrial whey samples, leading to the isolation of forty three genetically different lactococcal phages. Using multiplex PCR, all phages were identified as members of the 936 group. The complete genome of thirty eight of these phages was determined using next generation sequencing technologies which identified several regions of divergence. These included the structural region surrounding the major tail protein, the replication region as well as the genes involved in phage DNA packing. For a number of phages the latter genomic region was found to harbour genes encoding putative orphan methyltransferases. Using small molecule real time (SMRT) sequencing and heterologous gene expression, the target motifs for several of these MTases were determined and subsequently shown to actively protect phage DNA from restriction endonuclease activity. Comparative analysis of the thirty eight phages with fifty two previously sequenced members of this group showed that the core genome consists of 28 genes, while the non-core genome was found to fluctuate irrespective of geographical location or time of isolation. This study highlights the continued need to perform large scale characterisation of the bacteriophage populations infecting industrial fermentation facilities in effort to further our understanding dairy phages and ways to control their proliferation.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Vertebrate eggs are arrested at Metaphase II by Emi2, the meiotic anaphase-promoting complex/cyclosome (APC/C) inhibitor. Although the importance of Emi2 during oocyte maturation has been widely recognized and its regulation extensively studied, its mechanism of action remained elusive. Many APC/C inhibitors have been reported to act as pseudosubstrates, inhibiting the APC/C by preventing substrate binding. Here we show that a previously identified zinc-binding region is critical for the function of Emi2, whereas the D-box is largely dispensable. We further demonstrate that instead of acting through a "pseudosubstrate" mechanism as previously hypothesized, Emi2 can inhibit Cdc20-dependent activation of the APC/C substoichiometrically, blocking ubiquitin transfer from the ubiquitin-charged E2 to the substrate. These findings provide a novel mechanism of APC/C inhibition wherein the final step of ubiquitin transfer is targeted and raise the interesting possibility that APC/C is inhibited by Emi2 in a catalytic manner.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Phosphorylation of the beta(2) adrenoreceptor (beta(2)AR) by cAMP-activated protein kinase A (PKA) switches its predominant coupling from stimulatory guanine nucleotide regulatory protein (G(s)) to inhibitory guanine nucleotide regulatory protein (G(i)). beta-Arrestins recruit the cAMP-degrading PDE4 phosphodiesterases to the beta(2)AR, thus controlling PKA activity at the membrane. Here we investigate a role for PDE4 recruitment in regulating G protein switching by the beta(2)AR. In human embryonic kidney 293 cells overexpressing a recombinant beta(2)AR, stimulation with isoprenaline recruits beta-arrestins 1 and 2 as well as both PDE4D3 and PDE4D5 to the receptor and stimulates receptor phosphorylation by PKA. The PKA phosphorylation status of the beta(2)AR is enhanced markedly when cells are treated with the selective PDE4-inhibitor rolipram or when they are transfected with a catalytically inactive PDE4D mutant (PDE4D5-D556A) that competitively inhibits isoprenaline-stimulated recruitment of native PDE4 to the beta(2)AR. Rolipram and PDE4D5-D556A also enhance beta(2)AR-mediated activation of extracellular signal-regulated kinases ERK12. This is consistent with a switch in coupling of the receptor from G(s) to G(i), because the ERK12 activation is sensitive to both inhibitors of PKA (H89) and G(i) (pertussis toxin). In cardiac myocytes, the beta(2)AR also switches from G(s) to G(i) coupling. Treating primary cardiac myocytes with isoprenaline induces recruitment of PDE4D3 and PDE4D5 to membranes and activates ERK12. Rolipram robustly enhances this activation in a manner sensitive to both pertussis toxin and H89. Adenovirus-mediated expression of PDE4D5-D556A also potentiates ERK12 activation. Thus, receptor-stimulated beta-arrestin-mediated recruitment of PDE4 plays a central role in the regulation of G protein switching by the beta(2)AR in a physiological system, the cardiac myocyte.