Model-based analyses: Promises, pitfalls, and example applications to the study of cognitive control

We discuss a recent approach to investigating cognitive control, which has the potential to deal with some of the challenges inherent in this endeavour. In a model-based approach, the researcher defines a formal, computational model that performs the task at hand and whose performance matches that of a research participant. The internal variables in such a model might then be taken as proxies for latent variables computed in the brain. We discuss the potential advantages of such an approach for the study of the neural underpinnings of cognitive control and its pitfalls, and we make explicit the assumptions underlying the interpretation of data obtained using this approach

New insights into the genetic etiology of Alzheimer's disease and related dementias

Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

Condorcet final report

The Condorcet project was funded by the Dutch Technology Foundation (STW) through the Werkgemeenschap Informatiewetenschap. The project was carried out at the Vossius Laboratory of the University of Twente.\ud The main objective of the Condorcet project was to design, build and evaluate a prototype automated indexing system, supporting Information Retrieval from large, reality-level volumes (tens of thousands) of documents. The prototype has been tested on some 400 documents from two scientific domains: mechanical properties of engineering ceramics as a field of engineering, and epilepsy as a subfield of medicine.\ud The Condorcet system is concerned with semi-automatic indexing of documents, thus producing document representations, to be used in matching user requests to these representations. More specifically, the Condorcet system indexes scientific documents by mapping titles and abstracts (henceforth referred to as descriptions) of the documents to concepts and relations, defined in modern versions of classical indexing thesauri, i.e. ontologies. It does so by using \ud three kinds of knowledge: domain knowledge, linguistic knowledge and indexing knowledge

Incoherent versus coherent matched mode processing for shallow water source localisation using a single hydrophone

The aim of this paper is to propose a method of source localization using a single hydrophone in shallow water. To perform this localization, modes are first filtered in the time-frequency plane and then used in two different Matched Mode Processors: Incoherent and Coherent broadband processors. Results on simulated data are presented

Ontology - based integration of topographic data sets

The integration of topographic data sets is defined as the process of establishing relationships between corresponding object instances in different, autonomously produced, topographic data sets of the same geographic space. The problem of integrating topographic data sets is in finding these relationships, considering the differences in content and abstraction. A conceptual framework is developed. Components of this framework are ontologies and sets of surveying rules. New in this approach is the introduction of a reference model. A reference model belongs uniquely to the combination of topographic data sets to be integrated. The framework is tested on two topographic data sets with area instances (polygons) which have crisp and complete boundaries and are not displaced for cartographic reasons. The overall conclusion is that the ontology-based framework is feasible, if (1) there is (at least partial) knowledge of the surveying rules, and (2) the data sets can be synchronized in time. The application of this framework is most suitable for object classes with instances that are easy to identify and have a limited spatial extent (e.g., buildings). (c) 2005 Elsevier B.V. All rights reserved