Parallel computing and molecular dynamics of biological membranes

In this talk I discuss the general question of the portability of Molecular Dynamics codes for diffusive systems on parallel computers of the APE family. The intrinsic single precision arithmetics of the today available APE platforms does not seem to affect the numerical accuracy of the simulations, while the absence of integer addressing from CPU to individual nodes puts strong constraints on the possible programming strategies. Liquids can be very satisfactorily simulated using the "systolic" method. For more complex systems, like the biological ones at which we are ultimately interested in, the "domain decomposition" approach is best suited to beat the quadratic growth of the inter-molecular computational time with the number of elementary components of the system. The promising perspectives of using this strategy for extensive simulations of lipid bilayers are briefly reviewed.Comment: 4 pages LaTeX, 2 figures included, espcrc2.sty require

Luciano Erba: l'ultima intervista

This is the transcript of the last interview of Luciano Erba, held in February 2008, when the poet visited the Italian Department of the University of Reading as part of a UK tour to celebrate the publication of The Greener Meadow: Selected Poems, the English translation of his poetry by Peter Robinson, issued by Princeton University Press in 2006. The interview offered the opportunity to review Erba’s long career as a poet and assess the impact of some key cultural figures and events on his poetic

The rise and fall of Benedetto Croce: intellectual positionings in the Italian cultural field 1944-1947

This article evaluates the discourse developed around Benedetto Croce in the Italian cultural periodical press between 1944 and 1947 and it discusses the forms of adversarial discourse and the agents involved in the anti-Croce polemics that unfolded in the Communist party’s official cultural journal Rinascita. Specifically, this article focuses on a selection of intellectuals who moved away from Crocean idealism to embrace Marxism in order to investigate how their conversion was presented in Rinascita

Aretusa: continuity, rupture, and space for intervention, 1944-1946

This article focuses on the cultural activity of Aretusa (1944-1946), a journal that was deeply connected to the inner circle of philosopher and politician Benedetto Croce (1866-1952). The article analyses the role played by periodical editors Francesco Flora (1891-1962) and Carlo Muscetta (1912-2004) in shaping the mission and direction of this journal. By drawing on Pierre Bourdieu’s theory of habitus, and the notion of hysteresis in particular, this study details the factors influencing the aesthetic dispositions, political positioning, and the wider impact of historical circumstances on the cultural practice of each editor while at the helm of the review

Habitus and embeddedness in the Florentine literary field: the case of Alberto Carocci (1926-1939)

This article intends to show how the notion of embeddedness, a concept derived from network theory, can improve our understanding of how a journal’s reliance on regional and national intellectual networks impacts the journal’s performance. The study takes as test case Alberto Carocci’s editorship of Solaria. It also discusses — to a more limited extent — Giacomo Noventa (La riforma letteraria), and Berto Ricci (L’Universale). The study shows how uneven distribution of social capital (connections, links, etc.) across the members of the editorial board affects the journal’s embeddedness in existing networks. The article closes by arguing the need to focus on how journal editors develop their networks as a reaction to political pressure and in order to sustain competition in the marketplace

Molecular dynamics of C-peptide of ribonuclease A studied by replica-exchange Monte Carlo method and diffusion theory

Generalized-ensemble algorithm and diffusion theory have been combined in order to compute the dynamical properties monitored by nuclear magnetic resonance experiments from efficient and reliable evaluation of statistical averages. Replica-exchange Monte Carlo simulations have been performed with a C-peptide analogue of ribonuclease A, and Smoluchowski diffusion equations have been applied. A fairly good agreement between the calculated and measured $^1$H-NOESY NMR cross peaks has been obtained. The combination of these advanced and continuously improving statistical tools allows the calculation of a wide variety of dynamical properties routinely obtained by experiments.Comment: 17 pages, 5 figures, (LaTeX); Chemical Physics Letters, in pres

Mediating culture in the Italian literary field, 1940s-1950s: an introduction

This introduction lays out the scholarly and methodological context where to situate the contributions to this special issue. By combining a rigorous scrutiny of hitherto untapped archival sources with a re-examined application of Pierre Bourdieu’s sociology of culture within the field of periodical studies and publishing history in Italy (1940s-1950s), the studies illuminate the complex ways in which journals, periodical editors, and the connected publishing houses negotiate cultural practice in a literary field increasingly dominated by the polarization of political discourse

Ab initio simulations of Cu binding sites in the N-terminal region of PrP

The prion protein (PrP) binds Cu2+ ions in the octarepeat domain of the N-terminal tail up to full occupancy at pH=7.4. Recent experiments show that the HGGG octarepeat subdomain is responsible for holding the metal bound in a square planar coordination. By using first principle ab initio molecular dynamics simulations of the Car-Parrinello type, the Cu coordination mode to the binding sites of the PrP octarepeat region is investigated. Simulations are carried out for a number of structured binding sites. Results for the complexes Cu(HGGGW)+(wat), Cu(HGGG) and the 2[Cu(HGGG)] dimer are presented. While the presence of a Trp residue and a H2O molecule does not seem to affect the nature of the Cu coordination, high stability of the bond between Cu and the amide Nitrogens of deprotonated Gly's is confirmed in the case of the Cu(HGGG) system. For the more interesting 2[Cu(HGGG)] dimer a dynamically entangled arrangement of the two monomers, with intertwined N-Cu bonds, emerges. This observation is consistent with the highly packed structure seen in experiments at full Cu occupancy.Comment: 4 pages, conference proceedin