Long memory model of resting state functional MRI

Magdeburg, Univ., Fak. für Elektrotechnik und Informationstechnik, Diss., 2013

Neural correlates of context-dependent memory : the role of the insula in episodic encoding and recognition memory ; an fMRI experiment

Magdeburg, Univ., Med. Fak., Diss., 2014

Genetic influences on long-term memory control : COMT and retrieval-induced forgetting

Magdeburg, Univ., Med. Fak., Diss., 2014

A Novel Memory-centric Architecture and Organization of Processors and Computers

The modern computer systems that are in use nowadays are mostly processor-dominant, which means that their memory is treated as a slave element that has one major task – to serve execution units data requirements. This organization is based on the classical Von Neumann's computer model, proposed seven decades ago in the 1950ties. This model suffers from a substantial processor-memory bottleneck, because of the huge disparity between the processor and memory working speeds. In order to solve this problem, in this paper we propose a novel architecture and organization of processors and computers that attempts to provide stronger match between the processing and memory elements in the system. The proposed model utilizes a memory-centric architecture, wherein the execution hardware is added to the memory code blocks, allowing them to perform instructions scheduling and execution, management of data requests and responses, and direct communication with the data memory blocks without using registers. This organization allows concurrent execution of all threads, processes or program segments that fit in the memory at a given time. Therefore, in this paper we describe several possibilities for organizing the proposed memory-centric system with multiple data and logicmemory merged blocks, by utilizing a high-speed interconnection switching network.

Software for Explicitly Parallel Memory-Centric Processor Architecture

Advances in computer memory technology justify research towards new and different views on computer organization. This paper proposes a novel memory-centric computing architecture with the goal to merge memory and processing elements in order to provide better conditions for parallelization and performance. The paper introduces the architectural concepts and afterwards shows the design and implementation of a corresponding assembler and simulator.

Role of the neurotransmitters dopamine and acetylcholine during the interaction of working memory and attention

Magdeburg, Univ., Fak. für Naturwiss., Diss., 2015

Interneuron function in pathological memory processes : relevance for posttraumatic stress disorder

Otto-von-Guericke-Universität Magdeburg, Fakultät für Naturwissenschaften, Univ., Dissertation, 2015

Entomological contributions in memory of Byron A. Alexander / edited by George W. Byers, Robert H. Hagen and Robert W. Brooks.

no.24 (1999)

Does bounded rationality lead to individual heterogeneity? The impact of the experimentation process and of memory constraints

In this paper we explore the effect of bounded rationality on the convergence of individual behavior toward equilibrium. In the context of a Cournot game with a unique and symmetric Nash equilibrium, firms are modeled as adaptive economic agents through a genetic algorithm. Computational experiments show that (1) there is remarkable heterogeneity across identical but boundedly rational agents; (2) such individual heterogeneity is not simply a consequence of the random elements contained in the genetic algorithm; (3) the more rational agents are in terms of memory abilities and pre-play evaluation of strategies, the less heterogeneous they are in their actions. At the limit case of full rationality, the outcome converges to the standard result of uniform individual behavior.

Efficient and stable collective choices under gregarious preferences

We consider collective choice problems where a set of agents have to choose an alternative from a finite set and agents may or may not become users of the chosen alternative. An allocation is a pair given by the chosen alternative and the set of its users. Agents have gregarious preferences over allocations: given an allocation, they prefer that the set of users becomes larger. We require that the final allocation be efficient and stable (no agent can be forced to be a user and no agent who wants to be a user can be excluded). We propose a two-stage sequential mechanism whose unique subgame perfect equilibrium outcome is an efficient and stable allocation which also satisfies a maximal participation property.

Memory in contracts: the experience of the EBRD (1991-2003)

The objective of this paper is to identify the role of memory in repeated contracts with moral hazard in financial intermediation. We use the database we have built containing the contracts signed by the European Bank for Reconstruction and Development EBRD between 1991 and 2003. Our framework is a standard setting of repeated moral hazard. After having controlled for the adverse selection component, we are able to prove that client reputation is the discrimination device according to which the bank fixes the amount of credit for the established clients. Our results unambiguously isolate the effect of memory in the bank's lending decisions.

Constitutive activation of Wnt signaling favors generation of memory CD8 T cells.

T cell factor-1 (TCF-1) and lymphoid enhancer-binding factor 1, the effector transcription factors of the canonical Wnt pathway, are known to be critical for normal thymocyte development. However, it is largely unknown if it has a role in regulating mature T cell activation and T cell-mediated immune responses. In this study, we demonstrate that, like IL-7Ralpha and CD62L, TCF-1 and lymphoid enhancer-binding factor 1 exhibit dynamic expression changes during T cell responses, being highly expressed in naive T cells, downregulated in effector T cells, and upregulated again in memory T cells. Enforced expression of a p45 TCF-1 isoform limited the expansion of Ag-specific CD8 T cells in response to Listeria monocytogenes infection. However, when the p45 transgene was coupled with ectopic expression of stabilized beta-catenin, more Ag-specific memory CD8 T cells were generated, with enhanced ability to produce IL-2. Moreover, these memory CD8 T cells expanded to a larger number of secondary effectors and cleared bacteria faster when the immunized mice were rechallenged with virulent L. monocytogenes. Furthermore, in response to vaccinia virus or lymphocytic choriomeningitis virus infection, more Ag-specific memory CD8 T cells were generated in the presence of p45 and stabilized beta-catenin transgenes. Although activated Wnt signaling also resulted in larger numbers of Ag-specific memory CD4 T cells, their functional attributes and expansion after the secondary infection were not improved. Thus, constitutive activation of the canonical Wnt pathway favors memory CD8 T cell formation during initial immunization, resulting in enhanced immunity upon second encounter with the same pathogen.

B and T lymphocyte attenuator regulates CD8+ T cell-intrinsic homeostasis and memory cell generation.

B and T lymphocyte attenuator (BTLA) is a negative regulator of T cell activation, but its function in vivo is not well characterized. Here we show that mice deficient in full-length BTLA or its ligand, herpesvirus entry mediator, had increased number of memory CD8(+) T cells. The memory CD8(+) T cell phenotype resulted from a T cell-intrinsic perturbation of the CD8(+) T cell pool. Naive BTLA-deficient CD8(+) T cells were more efficient than wild-type cells at generating memory in a competitive antigen-specific system. This effect was independent of the initial expansion of the responding antigen-specific T cell population. In addition, BTLA negatively regulated antigen-independent homeostatic expansion of CD4(+) and CD8(+) T cells. These results emphasize two central functions of BTLA in limiting T cell activity in vivo.