Rose Sneyd translates Giuseppe Ungaretti

Rose Sneyd translates Giuseppe Ungarett

A Poetics of Reciprocity: Elizabeth Barrett Browning's Ballads and Sonnets

This thesis considers the way in which a selection of the poetry of Elizabeth Barrett Browning (henceforth to be referred to as EBB) exhibits what I will refer to as a poetics of reciprocity. My focus is on EBB’s ballads of the 1830s and 40s, her amatory sonnet sequence Sonnets from the Portuguese, and those ballads found in Last Poems. Lyric poetry is, traditionally, said to be defined by a monologic lyric speaker. Mikhail Bakhtin, for instance, pronounced that the mono-stylistic and cohesive nature of poetic language distinguished it from novelistic prose. However, it was, in part, Bakhtin’s insistence that poetry was by definition monologic that triggered my dialogic investigation of EBB’s poetry. Despite the range of work, both formal and temporal, that I consider in these three chapters, the discussion is nevertheless united by a consideration of EBB’s fascination with language, and her concomitant departure from the conventions of the monologic lyric speaker. In her early ballads, I explore EBB’s presentation of unreliable speakers and protagonists. These figures prove elusive to read because of their use of duplicitous or untrustworthy language, or they falter in the act of interpretation themselves. In EBB’s Sonnets from the Portuguese, I consider the way in which the poet opts for the language of conversation to evoke, in a fresh and powerful manner, the love between her speaker and her beloved. I suggest that this strategy, in part, compensated for the way in which clichéd literary language used to describe the experience of loving had been drained of vigour. Finally, in Last Poems I consider EBB’s presentation of speech as a social act that is influenced by the speaker’s status in society. In these late ballads, women’s attempts to wield language in an effective way are demonstrated to be dependent upon various conditions that reduce or enhance the potency of their speech acts. While Bakhtin’s essay “Discourse in the Novel,” in addition to the work of critics such as E. Warwick Slinn and Marjorie Stone, has been vital to the formulation of my thesis, I have, largely, relied upon a formalist approach to EBB’s poetry. In my close readings I examine EBB’s interrogation of language in her ballads and sonnets in light of her conscientious use, in particular, of metre and rhyme

Modeling Ca2+ Feedback on a Single Inositol 1,4,5-Trisphosphate Receptor and Its Modulation by Ca2+ Buffers

The inositol 1,4,5-trisphosphate receptor/channel (IP3R) is a major regulator of intracellular Ca2+ signaling, and liberates Ca2+ ions from the endoplasmic reticulum in response to binding at cytosolic sites for both IP3 and Ca2+. Although the steady-state gating properties of the IP3R have been extensively studied and modeled under conditions of fixed [IP3] and [Ca2+], little is known about how Ca2+ flux through a channel may modulate the gating of that same channel by feedback onto activating and inhibitory Ca2+ binding sites. We thus simulated the dynamics of Ca2+ self-feedback on monomeric and tetrameric IP3R models. A major conclusion is that self-activation depends crucially on stationary cytosolic Ca2+ buffers that slow the collapse of the local [Ca2+] microdomain after closure. This promotes burst-like reopenings by the rebinding of Ca2+ to the activating site; whereas inhibitory actions are substantially independent of stationary buffers but are strongly dependent on the location of the inhibitory Ca2+ binding site on the IP3R in relation to the channel pore

A Kinetic Model of Single and Clustered IP3 Receptors in the Absence of Ca2+ Feedback

Ca2+ liberation through inositol 1,4,5-trisphosphate receptor (IP3R) channels generates complex patterns of spatiotemporal cellular Ca2+ signals owing to the biphasic modulation of channel gating by Ca2+ itself. These processes have been extensively studied in Xenopus oocytes, where imaging studies have revealed local Ca2+ signals (“puffs”) arising from clusters of IP3R, and patch-clamp studies on isolated oocyte nuclei have yielded extensive data on IP3R gating kinetics. To bridge these two levels of experimental data, we developed an IP3R model and applied stochastic simulation and transition matrix theory to predict the behavior of individual and clustered IP3R channels. The channel model consists of four identical, independent subunits, each of which has an IP3-binding site together with one activating and one inactivating Ca2+-binding site. The channel opens when at least three subunits undergo a conformational change to an “active” state after binding IP3 and Ca2+. The model successfully reproduces patch-clamp data; including the dependence of open probability, mean open duration, and mean closed duration on [IP3] and [Ca2+]. Notably, the biexponential distribution of open-time duration and the dependence of mean open time on [Ca2+] are explained by populations of openings involving either three or four active subunits. As a first step toward applying the single IP3R model to describe cellular responses, we then simulated measurements of puff latency after step increases of [IP3]. Assuming that stochastic opening of a single IP3R at basal cytosolic [Ca2+] and any given [IP3] has a high probability of rapidly triggering neighboring channels by calcium-induced calcium release to evoke a puff, optimal correspondence with experimental data of puff latencies after photorelease of IP3 was obtained when the cluster contained a total of 40–70 IP3Rs