Tobias Emrich

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The challenges associated with handling uncertain data, in particular with querying and mining, are finding increasing attention in the research community. Here we focus on clustering uncertain data and describe a general framework for this purpose that also allows to visualize and understand the impact of uncertainty—using different uncertainty models—on(More)
Many applications require to determine the k-nearest neighbors for multiple query points simultaneously. This task is known as all-(k)-nearest-neighbor (AkNN) query. In this paper, we suggest a new method for efficient AkNN query processing which is based on spherical approximations for indexing and query set representation. In this setting, we propose(More)
Given a query object q, a reverse nearest neighbor (RNN) query in a common certain database returns the objects having q as their nearest neighbor. A new challenge for databases is dealing with uncertain objects. In this paper we consider probabilistic reverse nearest neighbor (PRNN) queries, which return the uncertain objects having the query object as(More)
Fast query processing of complex objects, e.g. spatial or uncertain objects, depends on efficient spatial pruning of objects' approximations, which are typically minimum bounding rectangles (MBRs). In this paper, we propose a novel effective and efficient criterion to determine the spatial topology between multi-dimensional rectangles. Given three(More)
The G-protein-coupled receptor BLR1 related to receptors for chemokines and neuropeptides has been identified as the first lymphocyte-specific member of the gene family characterized by seven transmembrane-spanning regions. Using a high-affinity anti-BLR1 monoclonal antibody (MoAb) and three-color flow cytometry it is shown that BLR1 expression on(More)
The putative chemokine receptor BLR1 has been identified as the first G-protein-coupled receptor involved in B-cell migration and in microenvironmental homing to B-cell follicles and to germinal centers. In healthy individuals, expression of BLR1 is restricted to all mature recirculating B cells and to a subpopulation of T-helper memory cells. In the(More)
The problem of modeling and managing uncertain data has received a great deal of interest, due to its manifold applications in spatial, temporal, multimedia and sensor databases. There exists a wide range of work covering spatial uncertainty in the static (snapshot) case, where only one point of time is considered. In contrast, the problem of modeling and(More)
Automatically determining the relative position of a single CT slice within a full body scan provides several useful functionalities. For example, it is possible to validate DICOM meta-data information. Furthermore, knowing the relative position in a scan allows the efficient retrieval of similar slices from the same body region in other volume scans.(More)
Deregulation of the proto-oncogene MYC by specific chromosomal translocations has been shown to be essential but not sufficient for the development of Burkitt's lymphoma (BL). To identify other genes which either mark important steps in tumorigenesis or which reflect the cellular differentiation state of BL cells we have compared tumor cells to immortalized(More)
Telomerase activity is necessary and sufficient for immortality in many cells and hence represents a prime target for antitumor strategies. Here, we show that a hammerhead ribozyme cleaves human telomerase (hTERT) mRNA in vitro. Stable transfection in clones of the human breast tumor line MCF-7 and the immortal breast cell line HBL-100 results in expression(More)