10 research outputs found

    Evolution of communities of software: using tensor decompositions to compare software ecosystems

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    © 2019 The Authors. Published by Springer. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.1007/s41109-019-0193-5Modern software development is often a collaborative effort involving many authors through the re-use and sharing of code through software libraries. Modern software “ecosystems” are complex socio-technical systems which can be represented as a multilayer dynamic network. Many of these libraries and software packages are open-source and developed in the open on sites such as , so there is a large amount of data available about these networks. Studying these networks could be of interest to anyone choosing or designing a programming language. In this work, we use tensor factorisation to explore the dynamics of communities of software, and then compare these dynamics between languages on a dataset of approximately 1 million software projects. We hope to be able to inform the debate on software dependencies that has been recently re-ignited by the malicious takeover of the npm package and other incidents through giving a clearer picture of the structure of software dependency networks, and by exploring how the choices of language designers—for example, in the size of standard libraries, or the standards to which packages are held before admission to a language ecosystem is granted—may have shaped their language ecosystems. We establish that adjusted mutual information is a valid metric by which to assess the number of communities in a tensor decomposition and find that there are striking differences between the communities found across different software ecosystems and that communities do experience large and interpretable changes in activity over time. The differences between the elm and R software ecosystems, which see some communities decline over time, and the more conventional software ecosystems of Python, Java and JavaScript, which do not see many declining communities, are particularly marked.OAB’s work was supported as part of an Engineering and Physical Sciences Research Council (EPSRC) grant, project reference EP/I028099/1.Published versio

    Nouveau Closo-decahydrodecaborate silane précurseurs et leur incorporation dans des matrices de silice.

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    De nouveaux prĂ©curseurs borates-triĂ©thoxysilanes comprenant le closo-decahydrodecaborate ont Ă©tĂ© prĂ©parĂ©s et immobilisĂ©s dans la silice. L'introduction des groupements trialkoxysilyles sur les clusters (NH4)2B10H10, a Ă©tĂ© rĂ©alisĂ©e par condensations Ă©lectrophiles faisant appel Ă  des rĂ©actifs nuclĂ©ophiles dans des conditions douces, tout en Ă©pargnant l'utilisation d'Ă©lectrophiles ou de catalyseurs coĂ»teux. Les borates-trialkoxysilanes obtenus ont Ă©tĂ© caractĂ©risĂ©s par RMN 1H, 13C, 11B, 29Si, 31P, IRTF, analyse Ă©lĂ©mentaire et spectroscopie de masse. Comme preuve de concept, ces prĂ©curseurs ont Ă©tĂ© incorporĂ©s de maniĂšre covalente dans les pores d'une silice mĂ©soporeuse, SBA-15. Tous les matĂ©riaux hybrides mĂ©soporeux et modifiĂ©s avec du borate-triĂ©thoxysilane ont Ă©tĂ© caractĂ©risĂ©s par RMN solide 11B et 29Si, DRX, MET, les analyses Ă©lĂ©mentaires et Ă©tude de l'adsorption d'azote (mĂ©thode BET). Les prĂ©curseurs silylĂ©s-borate ont Ă©tĂ© combinĂ©s avec des nanoparticules de silice pour une utilisation Ă©ventuelle dans BNCT, oĂč des NPs d'environ 100 nm ont Ă©tĂ© synthĂ©tisĂ©es comprenant deux types de centres luminescents diffĂ©rents. FITC silylĂ© (isothiocyanate de fluorescĂ©ine) et complexe Eu (III) silylĂ© ont Ă©tĂ© respectivement immobilisĂ©s dans des nanoparticules de silice par le procĂ©dĂ© sol-gel. Les deux types de nanoparticules luminescentes ont Ă©tĂ© fonctionnalisĂ©s par les groupes silylĂ©s-borates et caractĂ©risĂ©s par RMN du solide 11B, 31P et 29Si, DLS, MET, analyses Ă©lĂ©mentaires, d'adsorption d'azote et spectrophotomĂ©trie.New borate-triethoxysilane precursors comprising the closo-decahydrodecaborate cluster were prepared and immobolized into hybrid silica materials. The synthesis of silylated clusters starting from (NH4)2B10H10 and silane precursors R-Si(OEt)3 through Electrophilic Induced Nucleophilic Reactions was performed under mild conditions, the silylated clusters were analyzed by 1H, 13C, 11B, 29Si, 31P NMR, IR, elemental analyses and mass spectroscopy ES-ESI. As a proof of concept, the borate-triethoxysilane precursors were covalently incorporated into the pores of mesoporous silica, SBA-15 type. All mesoporous materials modified with borate-triethoxysilane were characterized by 11B and 29Si solid state NMR, XRD, TEM, elemental analyses and Nitrogen sorption studies. The silylated-borate precursors were combined with dye-doped silica nanoparticles for possible future use in BNCT technique, where ~100 nm nanoparticles were synthesized comprising two different types of luminescent centers. Silylated FITC (fluorescein isothiocyanate) and silylated Eu(III) complexes were embedded into silica nanoparticles through sol-gel process. Both types of luminescent nanoparticles were functionalized with the silylated-borate clusters and characterized by 11B, 31P and 29Si solid state NMR, DLS, TEM, elemental analyses, Nitrogen sorption studies and spectrophotometer

    Multifunctional Silica Nanoparticles Modified via Silylated-Decaborate Precursors

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    A new class of multifunctional silica nanoparticles carrying boron clusters (10-vertex closo-decaborate) and incorporating luminescent centers (fluorescein) has been developed as potential probes/carriers for potential application in boron neutron capture therapy (BNCT). These silica nanoparticles were charged in situ with silylated-fluorescein fluorophores via the Stöber method and their surface was further functionalized with decaborate-triethoxysilane precursors. The resulting decaborate dye-doped silica nanoparticles were characterized by TEM, solid state NMR, DLS, nitrogen sorption, elemental analysis, and fluorescence spectroscopy
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