88 research outputs found
A minimal core calculus for Solidity contracts
The Ethereum platform supports the decentralized execution of smart
contracts, i.e. computer programs that transfer digital assets between users.
The most common language used to develop these contracts is Solidity, a
Javascript-like language which compiles into EVM bytecode, the language
actually executed by Ethereum nodes. While much research has addressed the
formalisation of the semantics of EVM bytecode, relatively little attention has
been devoted to that of Solidity. In this paper we propose a minimal calculus
for Solidity contracts, which extends an imperative core with a single
primitive to transfer currency and invoke contract procedures. We build upon
this formalisation to give semantics to the Ethereum blockchain. We show our
calculus expressive enough to reason about some typical quirks of Solidity,
like e.g. re-entrancy.Comment: arXiv admin note: substantial text overlap with arXiv:1905.0436
The Glycosyltransferase Repertoire of the Spikemoss Selaginella moellendorffii and a Comparative Study of Its Cell Wall
Spike mosses are among the most basal vascular plants, and one species, Selaginella moellendorffii, was recently selected for full genome sequencing by the Joint Genome Institute (JGI). Glycosyltransferases (GTs) are involved in many aspects of a plant life, including cell wall biosynthesis, protein glycosylation, primary and secondary metabolism. Here, we present a comparative study of the S. moellendorffii genome across 92 GT families and an additional family (DUF266) likely to include GTs. The study encompasses the moss Physcomitrella patens, a non-vascular land plant, while rice and Arabidopsis represent commelinid and non-commelinid seed plants. Analysis of the subset of GT-families particularly relevant to cell wall polysaccharide biosynthesis was complemented by a detailed analysis of S. moellendorffii cell walls. The S. moellendorffii cell wall contains many of the same components as seed plant cell walls, but appears to differ somewhat in its detailed architecture. The S. moellendorffii genome encodes fewer GTs (287 GTs including DUF266s) than the reference genomes. In a few families, notably GT51 and GT78, S. moellendorffii GTs have no higher plant orthologs, but in most families S. moellendorffii GTs have clear orthologies with Arabidopsis and rice. A gene naming convention of GTs is proposed which takes orthologies and GT-family membership into account. The evolutionary significance of apparently modern and ancient traits in S. moellendorffii is discussed, as is its use as a reference organism for functional annotation of GTs
Prognostic value of tissue-type plasminogen activator (tPA) and its complex with the type-1 inhibitor (PAI-1) in breast cancer
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