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Hearing with the Mind\u27s Eye: Nested Narratives in \u3ci\u3eSeven Against Thebes\u3c/i\u3e
Full text linkIn “Seven against Thebes”, Aeschylus embeds omens within a messenger speech that contains an extended ekphrasis of the warrior’s shields as they assemble for battle. This article argues that the shields work like nesting-dolls: they contain inscribed speech within ekphrasis within reported speech within dramatic dialogue. Through this complex interconnection between speech-acts, Aeschylus adopts the literary techniques used in “Iliad” Book 18 for Achilles’ shield and adapts them for tragedy. The ekphrastic shields draw attention to the craft and skill, mediated through dramatic performance, that go into molding such a work just as the Homeric poet does in molding Achilles’ shield
Introduction: Building a Student Empowerment and Partnership Programme Driving Innovation and Change across the Technological Higher Education Sector in Ireland
No full textFrom Design to Implementation: Developing a Learning Community to Understand Student-Instructor Partnerships in Clinical Education
Full text linkDid \u27Flipping the Script\u27 Flip Perceptions? The Impact of a Student-Led Teaching Conference
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Review of \u3ci\u3eWorld Socialist Cinema: Alliances, Affinities, and Solidarities in the Global Cold War\u3c/i\u3e, by Masha Salazkina
Full text linkMolybdenum Cofactor Model Reveals Remarkable Redox Activity at Both Molybdenum and the Pyranopterin Dithiolene Ligand
No full textThe molybdenum (Moco) and tungsten (Tuco) cofactors are uniquely found in pyranopterin dithiolene (PDT) molybdenum and tungsten enzymes, yet the roles of this electronically complex PDT ligand in the catalytic cycles of these enzymes has yet to be revealed. After more than a decade of effort, we have synthesized and characterized a model compound containing a reduced PDT ligand coordinated to a diamagnetic d2 low-spin Mo(4+) ion, mimicking the MoO(PDT) structure common to most Mo enzyme active sites. A combination of 1D and 2D NMR spectroscopies, augmented by molecular geometry optimization computations, confirms that both R,R- and S,S-diastereomers coexist in the synthetic final product. Redox processes at both the Mo ion and the pyranopterin are detected by cyclic voltammetry. The two-electron oxidant DCIP oxidizes the pterin component of the ligand in methanol, whereas no reaction occurs in aprotic acetonitrile. Addition of 1 equiv of the one-electron oxidant Fc+ stoichiometrically oxidizes the Mo(4+) ion to the paramagnetic d1 Mo(5+) species, a result supported by electron paramagnetic resonance (EPR) spectroscopy. However, the addition of more than 1 equiv of Fc+ results in oxidation of the reduced pyranopterin to yield a Mo(4+) complex of the oxidized pyranopterin dithiolene ligand, a result supported by both the cyclic voltammetry and electronic absorption titrations. The concrete examples from these model studies suggest how the unique electronic structure of the PDT ligand in Moco and Tuco may enable variable redox reactivity in enzymatic catalysis, highlighting its role as a complex noninnocent biological ligand
