Prevalence of BRCA1 in a hospital-based population of Dutch breast cancer patients

The prevalence of disease-related BRCA1 mutations was investigated in 642 Dutch breast cancer patients not selected for family history or age at diagnosis. They were tested for germline mutations in the BRCA1 gene using an assay which detects small deletions and insertions (DSDI), as well as the two major genomic founder deletions present in the Dutch population. Data on family history and bilateral breast cancer were obtained retrospectively. Ten protein truncating mutations were detected and one in-frame deletion with an unknown relation to disease risk. Four patients carried the Dutch founder deletion of exon 22. Based on these results the estimated prevalence of breast cancer in the general population in the Netherlands attributable to BRCA1 mutations is 2.1%. Under 40 years-of-age and under 50 years-of-age this prevalence is 9.5% and 6.4%, respectively. All mutation carriers were under 50 years-of-age at diagnosis of the first breast cancer, and five did not have any relative with breast cancer. The proportions of bilateral breast cancer in the mutation carriers and non-carriers did not differ from each other. These data indicate that in the general Dutch breast cancer population the great majority of BRCA1 mutations will be found in women diagnosed under 50 years-of-age. © 2000 Cancer Research Campaig

Anomalous Transient Current in Nonuniform Semiconductors

Nonequilibrium processes in semiconductors are considered with highly nonuniform initial densities of charge carriers. It is shown that there exist such distributions of charge densities under which the electric current through a sample displays quite abnormal behaviour flowing against the applied voltage. The appearance of this negative electric current is a transient phenomenon occurring at the initial stage of the process. After this anomalous negative fluctuation, the electric current becomes normal, i.e. positive as soon as the charge density becomes more uniform. Several possibilities for the practical usage of this effect are suggested.Comment: 1 file, 11 pages, RevTex, no figure

Cornetto: A Combinatorial Lexical Semantic Database for Dutch

One of the goals of the STEVIN programme is the realisation of a digital infrastructure that will enforce the position of the Dutch language in the modern information and communication technology.A semantic database makes it possible to go from words to concepts and consequently, to develop technologies that access and use knowledge rather than textual representations

Conceptual framework for scenarios development in the Water futures and Solutions project

The major purpose of the Water Futures & Solutions (WFaS) initiative is to develop a set of adaptable resilient and robust solutions and a framework to facilitate access to and guidance through them by decision makers facing a variety of water-related challenges to sustainable evelopment, and a set of optional pathways to achieve plausible sustainable development goals by 2050. The WFaS Initiative addresses the multidimensional aspects of the water system and is guided by stakeholders representing these various aspects. The Initiative views freshwater systems as being strongly interweaved with human activities (Economy, Society) and Nature as a whole. Dynamics and health of freshwater systems is critical to human well- being. The Initiative will go beyond scenario production and model comparisons and will focus on exploring solutions and necessary innovations to address the growing water challenges. Solutions can be combinations of technological innovations, regulatory approaches, manageent or institutional changes that improve the balance of water supply and demand, improve water quality, or reduce water-related risks for society. Solutions will often be embedded in and cut across all sectors of social and economic activities. In order to represent the aspirations and interdependencies as described above, the conceptual framework has been developed, to communicate project results to the target audiences. This document describes this conceptual framework that will be used: -to support development of qualitative water scenarios -to identify and select critical dimensions of the water scenarios -to guide integration of scenarios with quantitative models -to guide integration of information from various data sources into the scenarios -to support development and assessment of solutions -to support collaboration between project and stakeholder groups -to facilitate presentation of results to target audiences The WFaS conceptual framework is developed using the 'concept maps' technique (Caqas and Carff, 2005; Novak and Caqas, 2006b). Concept maps method was develop to represent knowledge in an organized way. It allows practitioners to represent concepts and specific relationships between concepts. It is flexible enough to adapt to different knowledge domains to support better understanding and communication between individuals and groups from different backgrounds

Simulations of lattice animals and trees

The scaling behaviour of randomly branched polymers in a good solvent is studied in two to nine dimensions, using as microscopic models lattice animals and lattice trees on simple hypercubic lattices. As a stochastic sampling method we use a biased sequential sampling algorithm with re-sampling, similar to the pruned-enriched Rosenbluth method (PERM) used extensively for linear polymers. Essentially we start simulating percolation clusters (either site or bond), re-weigh them according to the animal (tree) ensemble, and prune or branch the further growth according to a heuristic fitness function. In contrast to previous applications of PERM, this fitness function is {\it not} the weight with which the actual configuration would contribute to the partition sum, but is closely related to it. We obtain high statistics of animals with up to several thousand sites in all dimension 2 <= d <= 9. In addition to the partition sum (number of different animals) we estimate gyration radii and numbers of perimeter sites. In all dimensions we verify the Parisi-Sourlas prediction, and we verify all exactly known critical exponents in dimensions 2, 3, 4, and >= 8. In addition, we present the hitherto most precise estimates for growth constants in d >= 3. For clusters with one site attached to an attractive surface, we verify the superuniversality of the cross-over exponent at the adsorption transition predicted by Janssen and Lyssy. Finally, we discuss the collapse of animals and trees, arguing that our present version of the algorithm is also efficient for some of the models studied in this context, but showing that it is {\it not} very efficient for the `classical' model for collapsing animals.Comment: 17 pages RevTeX, 29 figures include