19 research outputs found
Critical properties of the four-state commutative random permutation glassy Potts model in three and four dimensions
No full textWe investigate the critical properties of the four-state commutative random permutation glassy Potts model in three and four dimensions by means of Monte Carlo simulations and a finite-size scaling analysis. By using a field programmable gate array, we have been able to thermalize a large number of samples of systems with large volume. This has allowed us to observe a spin-glass ordered phase in d=4 and to study the critical properties of the transition. In d=3, our results are consistent with the presence of a Kosterlitz-Thouless transition, but also with different scenarios: transient effects due to a value of the lower critical dimension slightly below 3 could be very important
"Feed my lambs" : the spiritual direction ministry of Calvinistic British Baptist Anne Dutton during the early years of the evangelical revival.
No full textThis dissertation contends that Anne Dutton (1692-1765) contributed a transatlantic ministry of spiritual direction to the Evangelical Revival in the early 1740s. The first chapter provides a historiographical review of Dutton's reception in the
eighteenth and nineteenth centuries and the state of contemporary scholarship of Dutton. The chapter concludes with a historical reflection on spiritual direction, situating Dutton in the tradition of Protestant epistolary spiritual counseling and the long history of women spiritual directors. Chapter two provides an analysis of Dutton's early life in light of the autobiographies of Anne and her husband, Benjamin Dutton. The third chapter demonstrates that Anne Dutton's early literary productions were grounded in the spiritual formation she received in High Calvinistic congregations that encouraged experiential biblicism and Puritan spirituality. Of particular influence upon Dutton was the Puritan Thomas Goodwin with his interpretations of the "ages of Christianity" and the "sealing of the Spirit." Chapter four reconstructs Dutton's early correspondence with Howell Harris, John Wesley, and George Whitefield. The chapter demonstrates that Dutton's Calvinistic spiritual writings were attractive to Harris and Whitefield (who in turn expanded her social-spiritual direction network) and suggests Dutton's direction to these men is best defined as spiritual confirmation. The fifth chapter examines Dutton's presence in the first evangelical magazine, the London Weekly Papers, as the anonymous "Friend in the Country." Published by Dutton's correspondent John Lewis, the magazine included several of Dutton's spiritual pieces and advertised a number of her published works. Dutton's contributions to this publication demonstrate her usefulness to Calvinistic Methodism and the extensiveness of her influence, albeit anonymous, on readers in England, Scotland, and America. Chapter six analyzes Dutton's Letter-Books published in the 1740s. These volumes exhibit her transatlantic influence and the defining elements of her personal spiritual direction. The Letter-Books reveal Dutton's correspondents relating to her as a spiritual director: one who was holy, knowledgeable, compassionate, wise, and discerning. The chapter concludes suggesting Dutton's Letter-Books reflect the expansion and contraction of Dutton's influence in the Evangelical Revival. A final chapter summarizes the contributions of this project to the study of Anne Dutton's life, spirituality, and ministry.by Michael D. Sciretti, Jr.Ph.D
"Feed my lambs" : the spiritual direction ministry of Calvinistic British Baptist Anne Dutton during the early years of the evangelical revival.
No full textThis dissertation contends that Anne Dutton (1692-1765) contributed a transatlantic ministry of spiritual direction to the Evangelical Revival in the early 1740s. The first chapter provides a historiographical review of Dutton's reception in the eighteenth and nineteenth centuries and the state of contemporary scholarship of Dutton. The chapter concludes with a historical reflection on spiritual direction, situating Dutton in the tradition of Protestant epistolary spiritual counseling and the long history of women spiritual directors. Chapter two provides an analysis of Dutton's early life in light of the autobiographies of Anne and her husband, Benjamin Dutton. The third chapter demonstrates that Anne Dutton's early literary productions were grounded in the spiritual formation she received in High Calvinistic congregations that encouraged experiential biblicism and Puritan spirituality. Of particular influence upon Dutton was the Puritan Thomas Goodwin with his interpretations of the "ages of Christianity" and the "sealing of the Spirit." Chapter four reconstructs Dutton's early correspondence with Howell Harris, John Wesley, and George Whitefield. The chapter demonstrates that Dutton's Calvinistic spiritual writings were attractive to Harris and Whitefield (who in turn expanded her social-spiritual direction network) and suggests Dutton's direction to these men is best defined as spiritual confirmation. The fifth chapter examines Dutton's presence in the first evangelical magazine, the London Weekly Papers, as the anonymous "Friend in the Country." Published by Dutton's correspondent John Lewis, the magazine included several of Dutton's spiritual pieces and advertised a number of her published works. Dutton's contributions to this publication demonstrate her usefulness to Calvinistic Methodism and the extensiveness of her influence, albeit anonymous, on readers in England, Scotland, and America. Chapter six analyzes Dutton's Letter-Books published in the 1740s. These volumes exhibit her transatlantic influence and the defining elements of her personal spiritual direction. The Letter-Books reveal Dutton's correspondents relating to her as a spiritual director: one who was holy, knowledgeable, compassionate, wise, and discerning. The chapter concludes suggesting Dutton's Letter-Books reflect the expansion and contraction of Dutton's influence in the Evangelical Revival. A final chapter summarizes the contributions of this project to the study of Anne Dutton's life, spirituality, and ministry
Computational protein design with side-chain conformational entropy
No full textInternational audienceRecent advances in modeling protein structures at the atomic level have made it possible to tackle "de novo" computational protein design. Most procedures are based on combinatorial optimization using a scoring function that estimates the folding free energy of a protein sequence on a given main-chain structure. However, the computation of the conformational entropy in the folded state is generally an intractable problem, and its contribution to the free energy is not properly evaluated. In this article, we propose a new automated protein design methodology that incorporates such conformational entropy based on statistical mechanics principles. We define the free energy of a protein sequence by the corresponding partition function over rotamer states. The free energy is written in variational form in a pairwise approximation and minimized using the Belief Propagation algorithm. In this way, a free energy is associated to each amino acid sequence: we use this insight to rescore the results obtained with a standard minimization method, with the energy as the cost function. Then, we set up a design method that directly uses the free energy as a cost function in combination with a stochastic search in the sequence space. We validate the methods on the design of three superficial sites of a small SH3 domain, and then apply them to the complete redesign of 27 proteins. Our results indicate that accounting for entropic contribution in the score function affects the outcome in a highly nontrivial way, and might improve current computational design techniques based on protein stability
Monte Carlo simulations for statistical physics: Janus
No full textJanus is an FPGA-based computer optimized for the simulation of spin glasses or similar condensed matter systems.
Computing requirements in this area are still not met by available commercial systems, so an application-driven machine, boosting performance by approximately a factor 100x is in this case the only viable option to simulate large systems for a time window comparable with experiments
An In-Depth View of the Microscopic Dynamics of Ising Spin Glasses at Fixed Temperature
No full textUsing the special-purpose computer Janus, we follow the nonequilibrium dynamics of the Ising spin glass in three dimensions for eleven orders of magnitude. The use of integral estimators for the coherence and correlation lengths allows us to study dynamic heterogeneities and the presence of a replicon mode and to obtain safe bounds on the Edwards-Anderson order parameter below the critical temperature. We obtain good agreement with experimental determinations of the temperature-dependent decay exponents for the thermoremanent magnetization. This magnitude is observed to scale with the much harder to measure coherence length, a potentially useful result for experimentalists. The exponents for energy relaxation display a linear dependence on temperature and reasonable extrapolations to the critical point. We conclude examining the time growth of the coherence length, with a comparison of critical and activated dynamics
IANUS: an FPGA-based System for High Performance Scientific Computing
No full textApparso sugli archivi: arXiv:0710.353
