Many intracellular signal transduction processes involve the reversible translocation from the cytoplasm to the nucleus of transcription factors. The advent of fluorescently tagged protein derivatives has revolutionized cell biology, such that it is now possible to follow the location of such protein molecules in individual cells in real time. However, the quantitative analysis of the location of such proteins in microscopic images is very time consuming. We describe CellTracker, a software tool designed for the automated measurement of the cellular location and intensity of fluorescently tagged proteins. CellTracker runs in the MS Windows environment, is freely available (at http://www.dbkgroup.org/celltracker/), and combines automated cell tracking methods with powerful image-processing algorithms that are optimized for these applications. When tested in an application involving the nuclear transcription factor NF-kB, CellTracker is competitive in accuracy with the manual human analysis of such images but is more than 20 times faster, even on a small task where human fatigue is not an issue. This will lead to substantial benefits for time-lapse-based high-content screening.

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Model-based user interface development environments show promise for improving the productivity of user interface developers, and possibly for improving the quality of developed interfaces. While model-based techniques have previously been applied to the area of database interfaces, they have not been speci®cally targeted at the important area of object database applications. Such applications make use of models that are semantically richer than their relational counterparts in terms of both data structures and application functionality. In general, model-based techniques have not addressed how the information referenced in such applications is manifested within the described models, and is utilised within the generated interface itself. This lack of experience with such systems has led to many model-based projects providing minimal support for certain features that are essential to such data intensive applications, and has prevented object database interface developers in particular from bene®ting from model-based techniques. This paper presents the Teallach model-based user interface development environment for object databases, describing the models it supports, the relationships between these models, the tool used to construct interfaces using the models and the generation of Java programs from the declarative models. Distinctive features of Teallach include comprehensive facilities for linking models, a¯exible development method, an open architecture, and the generation of running applications based on the models constructed by designers.

Abstract— DNA replication in UV‐irradiated Chinese hamster V‐79 cells was analyzed by measuring the incorporation of 14C‐thymidine into acid precipitable form and by DNA fiber autoradiography. As expected, UV exposure resulted in a rapid deceleration in the rate of thymidine incorporation, reaching a minimum rate 60–75 min following exposure to 2–10Jm‐2. After an additional 1–2h the rate of thymidine incorporation began to recover slowly, approaching the control rate within 10h following exposure to 10 Jm‐2 or less. The mechanism of the inhibition and recovery in thymidine incorporation was examined by DNA fiber autoradiography. The results indicate that UV radiation produces lesions in DNA which temporarily block chain growth of DNA that is synthesized during the first 5 h after exposure. Within 10 h after exposure, the lesions have either been repaired or modified (or the replicative enzymes altered) so that DNA chain growth is no longer impeded.

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