2,799 research outputs found

    The Columbiad: Slavery, Imperialism and the Founding Fathers’ 'State of Fantasy'

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    The essay focuses on the discussion of slavery and emancipation between Atlas—the Guardian Genius of Africa—and Hesper—the Genius of America—in Joel Barlow’s epic poem The Columbiad (1807). The text shares Atlas’ words and describes slavery as an uncivil practice contrasting with the democratic principles of the new country. Nonetheless, the poem supports Hesper’s conviction that Africans’ exploitation is an essential tool to establish an American imperialistic “state of fantasy.” The paper tries to investigate this ideological paradox: Atlas’s dream of the Africans’ emancipation was engrained in the principles themselves of the Declaration of Independence; at the same time, Atlas’s aspiration had to be domesticated, if not repressed, by a Republic which aspired to turn itself into an Empire

    “ri-” e “di-”

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    Introduzione alla Special Section ri- e di-: Prefissi e paradigmi per rifare e disfare gli Stati Uniti dentro e fuori i confini

    AURIX TC277 Multicore Contention Model Integration for Automotive Applications

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    The ability to produce early guaranteed performance (worst-case execution time) estimates for multicores, i.e. before software from different providers gets integrated onto the same critical system, is pivotal. This helps reducing lately-detected costly-to-handle timing violations. An existing methodology creates ‘copy’ (surrogate) applications from the execution in isolation of each target application. Surrogate applications can be used to upperbound multicore contention delay, and hence WCET estimates in multicores. However, this methodology has only been shown to work on a simulation environment. In this paper we show the work we have carried out to adapt this technology to a real multicore processor for the space domain.The research leading to this work has received funding from the European Union’s H2020 programme under grant agreement No 644080 (SAFURE), by the Spanish Ministry of Economy and Competitiveness (MINECO) under grant TIN2015-65316-P and the HiPEAC Network of Excellence. Jaume Abella and Enrico Mezzetti have been partially sup-ported by MINECO under Ramon y Cajal and Juan de la Cierva-Incorporaci®on postdoctoral fellowships number RYC-2013-14717 and IJCI-2016-27396 respectively.Peer ReviewedPostprint (author's final draft

    Erratum: Lipase-catalyzed regioselective acylation of resorcin[4]arenes (Journal of Molecular Catalysis B: Enzymatic (2002) 16 (24-247) PII: S1381117701000686)

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    10Immobilized lipase from Mucor miehei (RML) catalyzed the regioselective acylation of the C-2 side-chain of the C-alkyl resorcin[4]arene tetra-alcohol 1 in the 1,2-alternate form in organic solvents using vinyl acetate as acylating reagent. The influence of reaction parameters and solvent choice were also studied. Docking simulations allowed the determination of the binding geometry of 1, revealing the importance of Trp88 residue in stabilizing the Michaelis–Menten complex between enzyme and substrate.reservedmixedBotta, Bruno; Zappia, Giovanni; Tafi, Andrea; Botta, Maurizio; Manetti, Fabrizio; Cernia, Enrico; Milana, Giuliana; Palocci, Cleofe; Soro, Simonetta; Delle Monache, GiulianoBotta, Bruno; Zappia, Giovanni; Tafi, Andrea; Botta, Maurizio; Manetti, Fabrizio; Cernia, Enrico; Milana, Giuliana; Palocci, Cleofe; Soro, Simonetta; Delle Monache, Giulian

    1H NMR Relaxometric Study of Chitosan-Based Nanogels Containing Mono- and Bis-Hydrated Gd(III) Chelates: Clues for MRI Probes of Improved Sensitivity

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    Hydrogel nanoparticles composed of chitosan and hyaluronate and incorporating Gd-based MRI contrast agents with different hydration number (e.g., [Gd(DOTA)(H2O)]− and [Gd(AAZTA)(H2O)2]−) were prepa..

    Revisiting paramagnetic relaxation enhancements in slowly rotating systems: how long is the long range?

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    Cross-relaxation terms in paramagnetic systems that reorient rigidly with slow tumbling times can increase the effective longitudinal relaxation rates of protons of more than 1 order of magnitude. This is evaluated by simulating the time evolution of the nuclear magnetization using a complete relaxation rate-matrix approach. The calculations show that the Solomon dependence of the paramagnetic relaxation rates on the metal–proton distance (as r−6) can be incorrect for protons farther than 15 Å from the metal and thus can cause sizable errors in R1-derived distance restraints used, for instance, for protein structure determination. Furthermore, the chemical exchange of these protons with bulk water protons can enhance the relaxation rate of the solvent protons by far more than expected from the paramagnetic Solomon equation. Therefore, it may contribute significantly to the water proton relaxation rates measured at magnetic resonance imaging (MRI) magnetic fields in the presence of slow-rotating nanoparticles containing paramagnetic ions and a large number of exchangeable surface protons

    Novel Nanogels Loaded with Mn(II) Chelates as Effective and Biologically Stable MRI Probes

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    Here it is described nanogels (NG) based on a chitosan matrix, which are covalently stabilized by a bisamide derivative of Mn-t-CDTA (t-CDTA = trans-1,2-diaminocyclohexane-N,N,N & PRIME;,N & PRIME;-tetraacetic acid). the Mn(II) complex acts both as a contrast medium and as a cross-linking agent. These nanogels are proposed as an alternative to the less stable paramagnetic nanogels obtained by electrostatic interactions between the polymeric matrix and paramagnetic Gd(III) chelates. The present novel nanogels show: i) relaxivity values seven times higher than that of typical monohydrated Mn(II) chelates at the clinical fields, thanks to the combination of a restricted mobility of the complex with a fast exchange of the metal-bound water molecule; ii) high stability of the formulation over time at pH 5 and under physiological conditions, thus excluding metal leaking or particles aggregation; iii) good extravasation and accumulation, with a maximum contrast achieved at 24 h post-injection in mice bearing subcutaneous breast cancer tumor; iv) high T-1 contrast (1 T) in the tumor 24 h post-injection. These improved properties pave the way for the use of these paramagnetic nanogels as promising magnetic resonance imaging (MRI) probes for in vitro and in vivo preclinical applications
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