55,162 research outputs found

    The properties of probabilistic simple regular sticker system

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    A mathematical model for DNA computing using the recombination behavior of DNA molecules, known as a sticker system, has been introduced in 1998. In sticker system, the sticker operation is based on the Watson-Crick complementary feature of DNA molecules. The computation of sticker system starts from an incomplete double-stranded sequence. Then by iterative sticking operations, a complete double-stranded sequence is obtained. It is known that sticker systems with finite sets of axioms and sticker rule (including the simple regular sticker system) generate only regular languages. Hence, different types of restrictions have been considered to increase the computational power of the languages generated by the sticker systems. In this paper, we study the properties of probabilistic simple regular sticker systems. In this variant of sticker system, probabilities are associated with the axioms, and the probability of a generated string is computed by multiplying the probabilities of all occurrences of the initial strings. The language are selected according to some probabilistic requirements. We prove that the probabilistic enhancement increases the computational power of simple regular sticker systems

    Incorporating DNA Sequencing into Current Prenatal Screening Practice for Down's Syndrome

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    PMCID: PMC3604109This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

    Quantitative studies of nucleic acid in the cell by micro-spectrophotometry I. The critique and improvement of the microspectrophotometry

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    Some critical experiments have been carried out on the microspectrophotometry using the lymphocytes of a mouse, stained with Feulgen reaction, revealing that most reliable value can be attained by illuminating the material with a small spot-light and integrating the area surrounded by the extinction curve drawn by tracing along the diameter of the smeared and fixed cell.</p
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