1,721,167 research outputs found
Omne vivum ex ovo: the oocyte reprogramming and remodeling activities
No full textThe mammalian oocyte is a unique cell, and comprehending its physiology and biology is essential for understanding fertilization, totipotency and early events of embryogenesis. Consequently, research in these areas influences the outcomes of various technologies, for example, the production and conservation of laboratory and large animals with rare and valuable genotypes, the rescue of the species near extinction, as well as success in human assisted reproduction. Nevertheless, even the most advanced and sophisticated reproductive technologies of today do not always guarantee a favorable outcome. Elucidating the interactions of oocyte components with its natural partner cell - the sperm or an 'unnatural' somatic nucleus, when the somatic cell nucleus transfer is used is essential for understanding how totipotency is established and thus defining the requirements for normal development. One of the crucial aspects is the stoichiometry of different reprogramming and remodeling factors present in the oocyte and their balance. Here, we discuss how these factors, in combination, may lead to the formation of a new organism. We focus on the laboratory mouse and its genetic models, as this species has been instrumental in shaping our understanding of early post-fertilization events
Oocyte activation is a cytoplasm-confined event so far; what about the nucleus?
No full textThe fertilizing spermatozoa induce a Ca2+ oscillatory pattern, the universal hallmark of oocyte activation, in all sexually reproducing animals. Assisted Reproductive Technologies (ARTs) like intracytoplasmic sperm injection (ICSI) bypass the physiological pathway; however, while a normal Ca2+ release pattern occurs in some species, particularly humans, artificial activation is compulsory for ICSI-fertilized oocytes to develop in most farm animals. Unlike the normal oscillatory pattern, most artificial activation protocols induce a single Ca2+ spike, undermining proper ICSI-derived embryo development in these species. Curiously, diploid parthenogenetic embryos activated by the same treatments develop normally at high frequencies and implant upon transfer in the uterus. We hypothesized that, at least in ruminant's embryos, the oscillatory calcium waves late in the first cell cycle target preferentially the paternal pronucleus and are fundamentally important for paternal nuclear remodeling. We believe that Ca2+ signaling is central to full totipotency deployment of the paternal genome. Research in this area could highlight the asymmetry between the parental genome reprogramming timing/mechanisms in early development and impact ARTs like ICSI and cloning
What does an invisible city look like
Get PDFThe subject of this thesis entitled What does an invisible city look like is the perception of a city and the way it is represented. The work is based on urban semiotics that sees urban environment as a particular system of communication. The methods of sensory urbanism and rhythm analysis are employed as well. The author asks whether the cities could be represented by other than visual symbols as it is usually the case for the products of tourism industry (guidebooks, souvenirs, etc.). Usually, the symbol of a particular city is formed by the image of its skyline. In Prague, this is the skyline of the Prague Castle, in Paris, it is the Eiffel tower, in New York, it is the Statue of Liberty, etc. But every city has definitely many other qualities. What are they? To find the answer, the author asks for help the visually impaired people. These people can tell easily what are the non-visual qualities of the urban space as they experience them necessarily in their everyday life and use them for better orientation. The author interviewed the visually impaired people and she also observed the way they read the city in real. The practical part of the thesis focuses on the Prague city centre
Development to term of sheep embryos reconstructed after inner cell mass/trophoblast exchange
Get PDFHere we report in vitro and term development of sheep embryos after the inner cell mass (ICM) from one set of sheep blastocysts were injected into the trophoblast vesicles of another set. We also observed successful in vitro development of chimeric blastocysts made from sheep trophoblast vesicles injected with bovine ICM. First, we dissected ICMs from 35 sheep blastocysts using a stainless steel microblade and injected them into 29 re-expanded sheep trophoblastic vesicles. Of the 25 successfully micromanipulated trophoblastic vesicles, 15 (51.7%) re-expanded normally and showed proper ICM integration. The seven most well reconstructed embryos were transferred for development to term. Three ewes receiving manipulated blastocysts were pregnant at day 45 (42.8%), and all delivered normal offspring (singletons, two females and one male, average weight: 3.54 ± 0.358 kg). Next, we monitored in vitro development of sheep trophoblasts injected with bovine ICMs. Of 17 injected trophoblastic vesicles, 10 (58.8%) re-expanded after 4 h in culture, and four (40%) exhibited integrated bovine ICM. Our results indicate that ICM/trophoblast exchange is feasible, allowing full term development with satisfactory lambing rate. Therefore, ICM exchange is a promising approach for endangered species conservation
Loki: transmedial narrative analysis of a trickster figure
No full textThis thesis covers the topics of transmedia narration of a trickster character with using examples from its mythological, poetic, film, serial and media representation. At first, Loki is defined as a character and as a trickster. Using transmedia narratology and storyworld theory, the author tries to discover whether it is possible to keep the trickster side of the character across genres and media formats
Le corps de la voix, la voix du corps. Marcel Proust et la musique spectrale
Get PDFThe present text explores Proustian aesthetics of music from a rather unusual point of view. After having briefly sketched the general outlines of Proust’s view of music (demonstrated by the famous passages on the “little phrase” from Vinteuil’s sonata), the author goes on to confront Proust with a more contemporary musical current – spectral music. As a starting point, we propose a close reading of several texts by Michaël Levinas – one of the founders of spectral music – stressing in particular what we consider to be a very important literary inspiration for one of Levinas’s compositions: the passage on the death agony of the narrator’s grand-mother from the third volume of In Search of Lost Time. This confrontation enables us, in turn, to read the Proustian text itself from a new perspective
An Image of War in Georges Bataille's Conceptions
No full textThe war represents one of the most conspicuous manifestations of the overabundance of energy that Georges Bataille has been theorizing as part of his theory of general economics. On the background of this facts, work seeks to define war as an inherently non-utilitarian expenditure of energy with which the human must necessarily contend. Next, the work attempts to question the common denominators of the excessive moments that war undoubtedly belongs to, and to point out their importance in philosophy of Bataille. The sovereignty that accompanies such moments will be further themed, bearing in mind the specificity that the author devotes to it, which breaks out of dialectical necessity. Keywords: Georges Bataille, sovereignty, accursed share, heterogeneity, self-consciousness, critique of utilitarity, wa
The limits of autobiography in Nebe nemá dno
No full textThis thesis, The limits of autobiography in Nebe nemá dno, explores the limits of the genre of autobiography, using the novel by Hana Androniková as an example. Using selected examples, it attempts to capture the motifs and references in which this novel transcends the defined conception of the autobiographical genre and thus stands on its borderline. Theoretical concepts dealing with the limits of the autobiographical genre and its contradictions is applied to this text. In its next part, this thesis follows selected story lines and contrasts them with real events in the author's life. The records and testimonies of the author herself, as well as those of her family and close friends, are also important material for this research
The simultaneity of the incompossible as the index of the vertical being in the philosophy of M. Merleau-Ponty
No full textRÉSUMÉ EN ANGLAIS / ENGLISH SUMMARY : The Simultaneity of the Incompossible as the Index of the Vertical Being in the Philosophy of M. Merleau-Ponty The principal field of investigation of this paper is the late philosophy of Maurice Merleau-Ponty in the form the author gave it in his lectures during the nineteen-fifties and in the project of The Visible and the Invisible. More accurately, the goal is to clarify the relationship between what this author calls "vertical" Being and the aspect of reciprocal exclusivity, or incompossibility, of the segments of the field through which we have access to it. This structural characteristic is studied principally on the levels of the perception, our relationships with the others, the language and other human institutions. First, the author of the paper elucidates what he think is the reference point of this ontological philosophy, that is to say the concept of visibility. By means of an interpretation of the three fundamental structures of the visibility, the visible, the invisible, and the vision (voyant), the author demonstrates the profound ontological unity of the element of the visibility. The concept of the "institution" (Stiftung, institution) is then introduced to demonstrate how the field of the visibility is internally organized in a manner that surpasses..
Simultaneita inkomposibilního jako index vertikálního bytí ve filosofii M. Merleau-Pontyho
Get PDFRÉSUMÉ EN ANGLAIS / ENGLISH SUMMARY : The Simultaneity of the Incompossible as the Index of the Vertical Being in the Philosophy of M. Merleau-Ponty The principal field of investigation of this paper is the late philosophy of Maurice Merleau-Ponty in the form the author gave it in his lectures during the nineteen-fifties and in the project of The Visible and the Invisible. More accurately, the goal is to clarify the relationship between what this author calls "vertical" Being and the aspect of reciprocal exclusivity, or incompossibility, of the segments of the field through which we have access to it. This structural characteristic is studied principally on the levels of the perception, our relationships with the others, the language and other human institutions. First, the author of the paper elucidates what he think is the reference point of this ontological philosophy, that is to say the concept of visibility. By means of an interpretation of the three fundamental structures of the visibility, the visible, the invisible, and the vision (voyant), the author demonstrates the profound ontological unity of the element of the visibility. The concept of the "institution" (Stiftung, institution) is then introduced to demonstrate how the field of the visibility is internally organized in a manner that surpasses...RÉSUMÉ EN TCHÈQUE / RÉSUMÉ V ČESKÉM JAZYCE : Simultaneita inkomposibilního jako index vertikálního Bytí ve filosofii M. Merleau-Pontyho Předmětem zkoumání této práce je pozdní filosofie Maurice Merleau- Pontyho v podobě, v jaké byla rozpracována v autorových přednáškách od padesátých let až do projektu knihy Viditelné a neviditelné. Přesněji řečeno jde o to objasnit principiálnost vztahu mezi tím, co u tohoto autora ozna- čuje pojem "vertikálního" Bytí, a rysem vzájemného vylučování neboli inkomposibility mezi úseky pole jevení, které nám toto Bytí otevírá, a to zejména v rovině vnímání, našich vztahů s ostatními lidmi, jazyka a dalších člověkem tvořených institucí. Text práce nejprve ukazuje, v jakém smyslu je třeba považovat za výchozí bod této filosofie pojem viditelnosti. Pomocí rozboru tří vnitřních strukturací tohoto "živlu" Bytí, tj. viditelného, neviditelného a vidoucího, autor obhajuje myšlenku zásadní ontologické jednotnosti této viditelnosti. V návaznosti na to práce zejména pomocí pojmu "instituce" ukazuje, jak je toto pole viditelnosti sobě vlastním způsobem vnitřně organizováno a v čem pojetí této strukturace překračuje novověkou ontologii subjektu a objektu, včetně kategorií, které implikuje. Tento výklad podle autora odhaluje metodologicko-ontologickou prioritu pojmu viditelnosti v...Institute of Philosophy and Religious StudiesÚstav filosofie a religionistikyFilozofická fakultaFaculty of Art
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