1,721,094 research outputs found
Mechanisms of amygdala facilitated cortico-striatal plasticity:
No full textThe amygdala is known to mediate the enhancing effects of emotional arousal on learning and memory. The increased firing rate of neurons in the basolateral complex of the amygdala (BLA) is believed to facilitate memory storage in various target structures, such as the striatum. Changes in the efficacy of cortical inputs to the striatum are thought to underlie motor learning and habit formation, making this pathway a perfect model to test the effects of BLA activity on synaptic plasticity and learning. My thesis provides evidence that BLA synapses have an N-methyl-D-aspartate receptor – to α-amino-5-hydroxy-3-methyl-4-isoxazole propionic acid receptor ratio higher than that of cortical synapses onto the same striatal neurons (Chapter 3). This property allows BLA inputs to facilitate the induction of heterosynaptic long term potentiation in vitro (Chapters 4 and 5). I also show that temporal coupling of BLA and striatal neurons in vivo occurs during coherent bursts of gamma activity observed in the local field potentials. Changes in the coherence of BLA-striatal gamma paralleled learning of a striatal-dependent task (Chapter 6). Together, these findings point towards a new mechanism of amygdala-facilitated learning.Ph.D.Includes bibliographical references (p. 111-123)by Andrei Tiberiu Popesc
A novice-friendly induction tactic for lean
No full textIn theorem provers based on dependent type theory such as Coq and Lean, induction is a fundamental proof method and induction tactics are omnipresent in proof scripts. Yet the ergonomics of existing induction tactics are not ideal: they do not reliably support inductive predicates and relations; they sometimes generate overly specific or unnecessarily complex induction hypotheses; and they occasionally choose confusing names for the hypotheses they introduce. This paper describes a new induction tactic, implemented in Lean 3, which addresses these issues. The tactic is particularly suitable for educational use, but experts should also find it more convenient than existing induction tactics. In addition, the tactic serves as a moderately complex case study for the metaprogramming framework of Lean 3. The paper describes some difficulties encountered during the implementation and suggests improvements to the framework
Machine-checked semantic session typing
Full text linkSession types- A family of type systems for message-passing concurrency-have been subject to many extensions, where each extension comes with a separate proof of type safety. These extensions cannot be readily combined, and their proofs of type safety are generally not machine checked, making their correctness less trustworthy. We overcome these shortcomings with a semantic approach to binary asynchronous affine session types, by developing a logical relations model in Coq using the Iris program logic. We demonstrate the power of our approach by combining various forms of polymorphism and recursion, asynchronous subtyping, references, and locks/mutexes. As an additional benefit of the semantic approach, we demonstrate how to manually prove typing judgements of racy, but safe, programs that cannot be type checked using only the rules of the type system. Programming Language
STRATEGICALLY REPOSITIONING RUSSIA
Full text linkPositioning is a very important marketing concept. Its importance was strongly emphasized and implemented in the case of companies, but is somehow neglected when it comes to states. A country acquires a position in the mind of a person very much like any other product does, which is very important especially when that person exerts an executive role. Nowadays Russia has a poor image or no image at all, both internationally and in Romania. In order to regain an important position in the Balkans region, Russia must set aside any political agenda and reposition itself as a business partner on equal terms. The first goal of this article is to clarify Russia's position in the minds of future Romanian executives. The second goal is to outline a recommended course of actions for Russia's repositioning.marketing, positioning, strategy, Russia, marketing research
DOES POSITIONING HAVE A PLACE IN THE MINDS OF OUR STUDENTS?
Full text linkPositioning is one of the most powerful marketing concepts. At the beginning, the meaning of positioning was rather limited, focusing on the concept of reputation. Then it became ”the place a brand occupies in the mind of its target audience”. Under this meaning , many companies have implemented the concept of positioning as a part of their everyday marketing activities. Nowadays, positioning is being used as a tool for explaining how consumers relate to foreign countries. The concept of positioning is simply to important to be ignored, but does it have a place in our students minds? This paper aims to determine whether we have an evolution or an involution in this matter.marketing, positioning, marketing research
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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