منابع مشابه
How to make an eye.
The eye is an organ of such remarkable complexity and apparently flawless design that it presents a challenge to both evolutionary biologists trying to explain its phylogenetic origins, and developmental biologists hoping to understand its formation during ontogeny. Since the discovery that the transcription factor Pax6 plays a crucial role in specifying the eye throughout the animal kingdom, b...
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The Chord distributed hash table (DHT) is well-known and frequently used to implement peer-to-peer systems. Chord peers find other peers, and access their data, through a ring-shaped pointer structure in a large identifier space. Despite claims of proven correctness, i.e., eventual reachability, formal modeling has shown that the Chord ring-maintenance protocol is not correct under its original...
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We describe a general construction of a module A from a given module B such that Ext(B,A) = 0 and we apply it to answer several questions on splitters, cotorsion theories, and saturated rings.
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With the high prevalence of gastrointestinal disorders, there is great interest in establishing in vitro models of human intestinal disease and in developing drug-screening platforms that more accurately represent the complex physiology of the intestine. We will review how recent advances in developmental and stem cell biology have made it possible to generate complex, three-dimensional, human ...
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ژورنال
عنوان ژورنال: Scientific American
سال: 1866
ISSN: 0036-8733
DOI: 10.1038/scientificamerican05261866-357