Search Results: 1 - 10 of 49 matches for " Anastassia Stoykova "
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Er81 is a downstream target of Pax6 in cortical progenitors
Tran Tuoc, Anastassia Stoykova
BMC Developmental Biology , 2008, DOI: 10.1186/1471-213x-8-23
Abstract: We identified and analyzed the regulatory function of an evolutionarily conserved upstream DNA sequence in the putative mouse Er81 promoter. Three potential Pax6 binding sites were identified in this region. We found that the presence of one of these sites is necessary and sufficient for full activation of the Er81 promoter in Pax6-transfected HeLa cells, while other still unknown factors appear to contribute to Er81 promoter activity in cortical progenitors and neuronal cells. The results suggest that endogenous Pax6, which is expressed at the highest level in progenitors of the rostrolateral cortex, exerts region-specific control of Er81 activity, thus specifying a subpopulation of layer 5 projection neurons.We conclude that the genetic interplay between the transcription factors, Pax6 and Er81, is responsible, in part, for the regional specification of a distinct sublineage of layer 5 projection neurons.In the mammalian neocortex (pallium), neurons with striking morphological and functional diversity are organized radially in six layers, and tangentially into numerous functional domains. Only recently have the molecular and cellular mechanisms that guide the process of corticogenesis responsible for this organization begun to be resolved [1,2]. The main source of cortical projection neurons is the population of pluripotent radial glial progenitors (RG), which divide asymmetrically at the apical surface of the ventricular zone (VZ) and generate both neuronal and glial progeny [3]. After midgestation, RG generate neuronal progenitors, termed intermediate or basal progenitors (BPs), that divide symmetrically at the basal surface of the VZ and in the subventricular zone (SVZ). Thus, while the asymmetric division of RG progenitors gives rise to progeny with distinct cell fates, the symmetric division of BPs primarily modulates the number of cells in previously established neuronal cell lineages [4]. The projection neurons of the lower (6 and 5) and upper (4–2) layers
Interaction between Axons and Specific Populations of Surrounding Cells Is Indispensable for Collateral Formation in the Mammillary System
Nora-Em?ke Szabó,Tianyu Zhao,Murat ?ankaya,Anastassia Stoykova,Xunlei Zhou,Gonzalo Alvarez-Bolado
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0020315
Abstract: An essential phenomenon during brain development is the extension of long collateral branches by axons. How the local cellular environment contributes to the initial sprouting of these branches in specific points of an axonal shaft remains unclear.
Democratization, Europeanization and Regionalization beyond the European Union: Search for Empirical Evidence
Obydenkova,Anastassia
European Integration Online Papers , 2006,
Abstract: This paper gives a viewpoint on a controversial issue of transnational regional cooperation (TRC) in Eurasia covering the analysis of cooperation between Europe and the regions of Russia. By promoting the favorable regime of transnational regional cooperation, both sides become more effective in managing such common problems as mutual security, political, economic and environmental challenges; illegal immigration; drug- and human-trafficking; etc. What is needed for the successful development of TRC in Eurasian context? What factors make a crucial impact on the development of regional cooperation, whether it is further "inclusion" or "exclusion" of the regions from cooperation with European neighbors? Is it the geopolitical location of the regions that makes regional cooperation more feasible or are there other factors that influence the success of this process? How might the regulatory and administrative tools of central government facilitate or complicate this process? To answer these questions, the study attempts to re-conceptualize the theories of integration, Europeanization, and regionalism. Then, it addresses the role of ethnicity, economical development, and geopolitical factors in the establishment and development of transnational regional cooperation. It also investigates the importance of "domestic-policy factors" (reforms in the federal governments) in the development of TRC.
Anastassia Obydenkova
La construction sociale de l'altérité en Grèce
Anastassia Tsoukala
Cahiers Balkaniques , 2011,
Abstract: L'état grec, à ses débuts, s'est appuyé sur une identité collective mythique qui a subi de graves traumatismes et doit aujourd'hui se reconstruire.La création de l'état grec moderne s'est appuyée sur une identité collective mythique, qui s'articulait autour d'une société prétendument homogène sur le plan démographique, d'une population éparpillée en dehors des frontières du pays qu'il convenait d'y intégrer en menant des guerres irrédentistes, et d'une continuité historique ininterrompue depuis l'Antiquité. L'arrivée massive des réfugiés grecs en 1922 a mis en rude épreuve cette identité nationale. Alors que l'état leur a immédiatement accordé des droits civiques, la majorité de la société leur a réservé un accueil hostile qui les a rapidement marginalisés. Un nouveau déchirement suivit, la guerre civile (1949), or, tout au long de sa durée et surtout une fois terminée, cette guerre fut niée, ou réduite à la seule figure du communiste manipulateur–manipulé qui permettait d'apporter des réponses réconfortantes à des questions douloureuses sur le plan politique, social et démographique du pays. Préserver cette image de la menace communiste a, donc, impliqué l'imposition du silence. Sa remise en question, récente, est-elle aussi en voie de construction. The Modern Greek state was created on the basis of a collective, mythical identity. This identity was predicated upon an allegedly homogeneous population scattered well beyond the borders of the country, with all its irredentist aspirations, and upon an imagined historical continuity that was uninterrupted since Antiquity. The massive arrival of Greek refugees in 1922 put this national identity severely to the test. Whereas the state immediately granted them civil rights, they were not welcomed by most of Greek society, which promptly marginalised them. A new rupture followed in the form of the Civil War (1949). In the course of this conflict, and more especially afterwards, the war was denied, or reduced to the lone figure of the communist—at once manipulator and manipulated—which made it possible to give comforting answers to the country's painful political, social and demographic questions. Preserving this image of the communist threat therefore necessitated silence—a silence only recently broken.
Local-Global principles for certain images of Galois representations
Anastassia Etropolski
Abstract: Let $K$ be a number field and let $E/K$ be an elliptic curve whose mod $\ell$ Galois representation locally has image contained in a group $G$, up to conjugacy. We classify the possible images for the global Galois representation in the case where $G$ is a Cartan subgroup or the normalizer of a Cartan subgroup. When $K = \mathbf{Q}$, we deduce a counterexample to the local-global principle in the case where $G$ is the normalizer of a split Cartan and $\ell = 13$. In particular, there are at least three elliptic curves (up to twist) over $\mathbf{Q}$ whose mod $13$ image of Galois is locally contained in the normalizer of a split Cartan, but whose global image is not.
Bulgarian Society of Individual Psychology
Zhaneta Stoykova,Tiha Delcheva
Psychological Thought , 2013, DOI: 10.5964/psyct.v6i1.59
Abstract: It has been two years since the Bulgarian Society of Individual Psychology was founded on the initiative of Trakia University faculty membersand students. On the occasion of its first anniversary, the goals of the Society and its activity over the course of the last year will be presentedin this article.
OPPORTUNITIES FOR ANALYTICAL COMPARISON IN THE NATIONAL ECONOMIES OF BULGARIA AND ROMANIA
Andreana STOYKOVA-KANALIEVA
Scientific Annals of the Alexandru Ioan Cuza University of Iasi : Economic Sciences Series , 2010,
Abstract: In the current economic situation the comparison of the degree of economic development be-tween the countries in United Europe is becoming more up-to-date. New approaches and tools for such comparison are being developed.This article offers a possible approach, focusing on the statistic analysis of growth and differ-ences. It is based on the modification of this method of analysis, proposed by V. Tzonev and T. Kunaliev. The method has been adapted for the needs of international comparative analyses in order to compare the GVA growth (Gross Value Added) based on growth sources in R. Bulgaria and R. Romania for the period from 2002 to 2007. The adjusted method is (has been) applied in three directions of analysis, focusing on their cognitive values. This specific comparative study has taken them into consideration, interpreting in details the obtained results.
Why Sociology Has a Marginal Position in Civic Education in Bulgaria Nationally Specific and/or Universal Trends
Georgi Dimitrov,Elena Stoykova
Journal of Social Science Education , 2009,
Abstract: The authors claim that, to an extent, the marginalization is a by-product of relationship among sociology, citizenship education and school education in general. This relationship is pretty complex and problematic because each of the three constituents undergoes a phase of fundamental crisis of axiological and institutional character. The developments in American sociology that exemplifies the state of affairs in the field are taken as point of departure while the Bulgarian case is used just as a magnifying glass to see clearer the triple crises which bring us to the roots of the civilizational transformation experienced today.The moral of the story is that sociology has been marginalized in last decades because its public and academic status won by the previous generation can not be taken for granted. It does not correspond to the pressing demands of the changing world for a different type of sociology. Thus sociology falls easy prey to the academic competitors who follow aggressive strategy and policy of public expansion even in civil education. The particular situation in other countries may be different but these are common general rules of construing sociology. At the end the paper offers some guidelines for transformation of the pattern in which contemporary sociology should be practiced in order to raise its public and civic relevance through refocusing it on sophisticated mediation of public policy and actions of citizens and through new forms of cultural communication.
Structures of Li-Doped Alkali Clusters are Dictated by AO-Hybridization
Anastassia N. Alexandrova
Abstract: Hybridization of atomic orbitals is a widely appreciated phenomenon whose impact on the structure and properties of, for example, organic molecules is well-established. Here, we demonstrate that hybridization also dramatically impacts the shapes of small alkali metal clusters. The seemingly similar and valence-iso-electronic LiNa4- and LiK4- clusters adopt very different global minimum structures: LiNa4- is a planar C2v (1A1) species distorted from the perfect pentagon due to the pseudo Jahn-Teller effect, and LiK4- is a planar square D4h (1A1g) species with Li being in the centre. This effect is rooted in the different degrees of the 2s-2p hybridization in Li in response to binding to Na versus K. Li inside the Na cluster exhibits a strong 2s-2p mixing, to achieve stronger covalent bonding. In contrast, Li inside of the K cluster does not show any hybridization, and the LiK4- cluster is reminiscent of an ionic salt. These differences are tied to the relative electronegativities of Li, Na, and K, and overlap of the valence atomic orbitals of Li with those of Na versus those of K. Atomic orbital hybridization is thus a pronounced effect in clusters, the understanding of which is important for the use of clusters in material science or catalysis, and designing clusters of desired shapes.