6 research outputs found
Outbreak of tropical rat mite (Ornithonyssus bacoti) dermatitis in a home for disabled persons
Five mentally handicapped individuals living in a home for disabled persons in Southern Germany were seen in our outpatient department with pruritic, red papules predominantly located in groups on the upper extremities, neck, upper trunk and face. Over several weeks 40 inhabitants and 5 caretakers were affected by the same rash. Inspection of their home and the sheds nearby disclosed infestation with rat populations and mites. Finally the diagnosis of tropical rat mite dermatitis was made by the identification of the arthropod Ornithonyssus bacoti or so-called tropical rat mite. The patients were treated with topical corticosteroids and antihistamines. After elimination of the rats and disinfection of the rooms by a professional exterminator no new cases of rat mite dermatitis occurred. The tropical rat mite is an external parasite occurring on rats, mice, gerbils, hamsters and various other small mammals. When the principal animal host is not available, human beings can become the victim of mite infestation. Copyright (c) 2007 S. Karger AG, Base
Sfrp3 modulates stromal-epithelial crosstalk during mammary gland development by regulating Wnt levels
Mammary stroma is essential for epithelial morphogenesis and development. Indeed, postnatal mammary gland (MG) development is controlled locally by the repetitive and bi-directional cross-talk between the epithelial and the stromal compartment. However, the signalling pathways involved in stromal–epithelial communication are not entirely understood. Here, we identify Sfrp3 as a mediator of the stromal–epithelial communication that is required for normal mouse MG development. Using Drosophila wing imaginal disc, we demonstrate that Sfrp3 functions as an extracellular transporter of Wnts that facilitates their diffusion, and thus, their levels in the boundaries of different compartments. Indeed, loss of Sfrp3 in mice leads to an increase of ductal invasion and branching mirroring an early pregnancy state. Finally, we observe that loss of Sfrp3 predisposes for invasive breast cancer. Altogether, our study shows that Sfrp3 controls MG morphogenesis by modulating the stromal-epithelial cross-talk during pubertal development
Built-in test for circuits with scan based on reseeding of multiple-polynomial linear feedback shift registers
In this paper, we propose a new scheme for Built-In Test (BIT) that uses Multiple-polynomial Linear Feedback Shift Registers (MP-LFSR's). The same MP-LFSR that generates random patterns to cover easy to test faults is loaded with seeds to generate deterministic vectors for difficult to test faults. The seeds are obtained by solving systems of linear equations involving the seed variables for the positions where the test cubes have specified values. We demonstrate that MP-LFSR's produce sequences with significantly reduced probability of linear dependence compared to single polynomial LFSR's. We present a general method to determine the probability of encoding as a function of the number of specified bits in the test cube, the length of the LFSR and the number of polynomials. Theoretical analysis and experiments show that the probability of encoding a test cube with s specified bits in an s-stage LFSR with 16 polynomials is 1–10^{-6}. We then present the new BIT scheme that allows for an efficient encoding of the entire test set. Here the seeds are grouped according to the polynomial they use and an implicit polynomial identification reduces the number of extra bits per seed to one bit. The paper also shows methods of processing the entire test set consisting of test cubes with varied number of specified bits. Experimental results show the tradeoffs between test data storage and test application time while maintaining complete fault coverage.Index Terms—Built-In Test, hardware test pattern generators, input test data compression and decompression, multiple-polynomial LFSR, reseeding, scan design
Generation of vector patterns through reseeding of multiple-polynomial linear feedback shift registers
A comparative analysis of the encoding efficiency of built-in-self-test (BIST) schemes based on reseeding of single polynomial linear fedback shift registers (LFSRs) as well as LFSRs with fully programmable polynomials is performed. Full programmability gives much better encoding efficiency. For a testcube with s carebits only s + 4 bits are required, in contrast to s + 19 bits for reseeding of single polynomials. A new BIST scheme is proposed in which the generator can operate according to a number of primitive polynomials. The testcubes are encoded as the polynomial identifier and a seed. Models of the encoding efficiency of this scheme are presented, and it is demonstrated, both theoretically and through extensive simulations, that such a scheme with 16 polynomials approaches the efficiency of the scheme based on full polynomial programmability, essentially preserving the computational simplicity of single reseeding
Long-term live imaging and multiscale analysis identify heterogeneity and core principles of epithelial organoid morphogenesis
Background: Organoids are morphologically heterogeneous three-dimensional cell culture systems and serve as an ideal model for understanding the principles of collective cell behaviour in mammalian organs during development, homeostasis, regeneration, and pathogenesis. To investigate the underlying cell organisation principles of organoids, we imaged hundreds of pancreas and cholangiocarcinoma organoids in parallel using light sheet and bright-field microscopy for up to 7 days. Results: We quantified organoid behaviour at single-cell (microscale), individual-organoid (mesoscale), and entireculture (macroscale) levels. At single-cell resolution, we monitored formation, monolayer polarisation, and degeneration and identified diverse behaviours, including lumen expansion and decline (size oscillation), migration, rotation, and multi-organoid fusion. Detailed individual organoid quantifications lead to a mechanical 3D agent-based model. A derived scaling law and simulations support the hypotheses that size oscillations depend on organoid properties and cell division dynamics, which is confirmed by bright-field microscopy analysis of entire cultures. Conclusion: Our multiscale analysis provides a systematic picture of the diversity of cell organisation in organoids by identifying and quantifying the core regulatory principles of organoid morphogenesis