808 research outputs found
Stephen Schofield
No full textTisseron analyses the multiple aspects of Schofield's recent soft-sculptures. The author notes their characteristic relationship with depth, links them to the preverbal experience of maternal touching, and examines the interface function of the materials. Artist's statement. Biographical notes. 11 bibl. ref
\u3cem\u3eInterpreting Artefact Scatters: Contributions to Ploughzone Archaeology\u3c/em\u3e, edited by A. J. Schofield
No full textA review of Interpreting Artefact Scatters: Contributions to Ploughzone Archaeology, edited by A. J. Schofield
Encountering a surprising response to cyberbullying among an immigrant community
No full textLynn Schofield Clark draws on her ethnographic research at a U.S. high school and reflects on the role of digital media in immigrant groups, online harassment and the opportunities provided by strong communities. Lynn is Professor and Chair in the Department of Media, Film, and Journalism Studies at the University of Denver. She is also the author of “The parent app: Understanding families in a digital age”, a book also recently reviewed on this blog
Mechanism and materialism: British natural philosophy in the age of reason
No full textRobert Schofield explores the rational elements of British experimental natural philosophy in the 18th century by tracing the influence of two opposing concepts of the nature of matter and its action-mechanism and materialism. Both concepts rested on the Newtonian interpretation of their proponents, although each developed more or less independently. By integrating the developments in all the areas of experimental natural philosophy, describing their connections and the influences of Continental science, natural theology, and to a lesser degree social and institutional changes, the author de
A 5′ UTR GGN repeat controls localisation and translation of a potassium leak channel mRNA through G-quadruplex formation
No full textRNA G-quadruplexes (G4s) are secondary structures proposed to function as regulators of post-transcriptional mRNA localisation and translation. G4s within some neuronal mRNAs are known to control distal localisation and local translation, contributing to distinct local proteomes that facilitate the synaptic remodelling attributed to normal cellular function. In this study, we characterise the G4 formation of a (GGN)13 repeat found within the 5′ UTR of the potassium 2-pore domain leak channel Task3 mRNA. Biophysical analyses show that this (GGN)13 repeat forms a parallel G4 in vitro exhibiting the stereotypical potassium specificity of G4s, remaining thermostable under physiological ionic conditions. Through mouse brain tissue G4-RNA immunoprecipitation, we further confirm that Task3 mRNA forms a G4 structure in vivo. The G4 is inhibitory to translation of Task3 in vitro and is overcome through activity of a G4-specific helicase DHX36, increasing K+ leak currents and membrane hyperpolarisation in HEK293 cells. Further, we observe that this G4 is fundamental to ensuring delivery of Task3 mRNA to distal primary cortical neurites. It has been shown that aberrant Task3 expression correlates with neuronal dysfunction, we therefore posit that this G4 is important in regulated local expression of Task3 leak channels that maintain K+ leak within neurons
Discontinuous molecular dynamics for semiflexible and rigid bodies
No full textA general framework for performing event-driven simulations of systems with semiflexible or rigid bodies interacting under impulsive forces is outlined. The method consists of specifying a means of computing the free evolution of constrained motion, evaluating the times at which interactions occur, and determining the consequences of interactions on subsequent motion. Algorithms for computing the times of interaction events and carrying out efficient event-driven simulations are discussed. The semiflexible case and the rigid case differ qualitatively in that the free motion of a rigid body can be computed analytically and need not be integrated numerically. (c) 2007 American Institute of Physics.PT: J; CR: ABRAMOWITZ M, 1965, HDB MATH FUNCTIONS F ALDER BJ, 1959, J CHEM PHYS, V31, P459 ALDER BJ, 1960, J CHEM PHYS, V33, P1439 ALLEN MP, 1987, COMPUTER SIMULATION ALLEN MP, 1989, COMPUT PHYS REP, V9, P301 ANDERSEN HC, 1983, J COMPUT PHYS, V52, P24 BARAFF D, 1989, COMPUT GRAPH, V23, P223 BARAFF D, 1992, THESIS CORNELL U BRENT RP, 1973, ALGORITHMS MINIMIZAT CARTER EA, 1989, CHEM PHYS LETT, V156, P472 CHAPELA GA, 1984, MOL PHYS, V53, P139 CHAPELA GA, 1989, CHEM PHYS, V129, P201 CICCOTTI G, 2004, J STAT PHYS, V115, P701 DELAPENA LH, UNPUB DELAPENA LH, 2005, J CHEM PHYS, V126 DEMICHELE C, 2006, J PHYS CHEM B, V110, P8064 DONEV A, 2005, J COMPUT PHYS, V202, P737 DONEV A, 2005, J COMPUT PHYS, V202, P765 ERPENBECK JJ, 1977, STAT MECH B FIXMAN M, 1974, P NATL ACAD SCI USA, V71, P3050 FRENKEL D, 2004, UNDERSTANDING MOL DY GALASSI M, 2005, GNU SCI LIB REFERENC GOLDSTEIN H, CLASSICAL MECH JACOBI CGJ, 1849, J CRELLE, V39, P293 KNOPP K, 1947, THEORY FUNCTIONS 2 LANDAU LD, 1976, MECHANICS LUBACHEVSKY BD, 1991, J COMPUT PHYS, V94, P255 MARIN M, 1993, J COMPUT PHYS, V109, P306 MARIN M, 1995, COMPUT PHYS COMMUN, V92, P214 MARSDEN JE, 2002, INTRO MECH SYMMETRY MASUTANI Y, 1994, P IEEE INT C ROB AUT, V2, P1066 MELCHIONNA S, 2000, PHYS REV E A, V61, P6165 MOSHIER SL, 1989, METHODS PROGRAMS MAT PRESS WH, 1992, NUMERICLA RECIPES FO RAMSHAW JD, 1986, PHYS LETT A, V116, P110 RAPAPORT DC, 1980, J COMPUT PHYS, V34, P184 RAPAPORT DC, 2004, ART MOL DYNAMICS SIM RUEB AS, 1834, THESIS UTRECHT NETHE RYCKAERT JP, 1977, J COMPUT PHYS, V23, P327 TUCKERMAN ME, 1999, EUROPHYS LETT, V45, P149 TUCKERMAN ME, 2001, J CHEM PHYS, V115, P1678 VANZON R, IN PRESS J COMPUT PH VANZON R, 2002, PHYS REV E 1, V65 WHITTAKER ET, 1937, TREATISE ANAL DYMANI; NR: 44; TC: 1; J9: J CHEM PHYS; PG: 13; GA: 138VLSource type: Electronic(1
Discontinuous molecular dynamics for rigid bodies: Applications
No full textEvent-driven molecular dynamics simulations are carried out on two rigid-body systems which differ in the symmetry of their molecular mass distributions. First, simulations of methane in which the molecules interact via discontinuous potentials are compared with simulations in which the molecules interact through standard continuous Lennard-Jones potentials. It is shown that under similar conditions of temperature and pressure, the rigid discontinuous molecular dynamics method reproduces the essential dynamical and structural features found in continuous-potential simulations at both gas and liquid densities. Moreover, the discontinuous molecular dynamics approach is demonstrated to be between 3 and 100 times more efficient than the standard molecular dynamics method depending on the specific conditions of the simulation. The rigid discontinuous molecular dynamics method is also applied to a discontinuous-potential model of a liquid composed of rigid benzene molecules, and equilibrium and dynamical properties are shown to be in qualitative agreement with more detailed continuous-potential models of benzene. The few qualitative differences in the angular dynamics of the two models are related to the relatively crude treatment of variations in the discontinuous repulsive interactions as one benzene molecule rotates by another. (c) 2007 American Institute of Physics.PT: J; CR: ALDER BJ, 1959, J CHEM PHYS, V31, P459 BELLEMANS A, 1980, MOL PHYS, V39, P781 CACELLI I, 2004, J AM CHEM SOC, V126, P14278 CHAPELA GA, 1984, MOL PHYS, V53, P139 CHAPELA GA, 1989, CHEM PHYS, V129, P201 DELAPENA LH, 2007, J CHEM PHYS, V126 DEMICHELE C, 2006, J PHYS CHEM B, V110, P8064 DING F, 2003, PROTEINS, V53, P220 DUANE S, 1987, PHYS LETT B, V195, P216 DULLWEBER A, 1997, J CHEM PHYS, V107, P5840 FALCONE DR, 1967, J PHYS CHEM-US, V71, P2754 MACKERELL AD, 1998, J PHYS CHEM B, V102, P3586 NGUYEN HD, 2006, J AM CHEM SOC, V128, P1890 PRESS WH, 1992, NUMERICLA RECIPES FO RAPAPORT DC, 1979, J CHEM PHYS, V71, P3299 RAPAPORT DC, 2004, ART MOL DYNAMICS SIM VANZON R, CONDMAT0612404 VANZON R, IN PRESS J COMPUT PH ZACHAROPOULOS N, 2005, J CHEM PHYS, V122 ZHOU YQ, 1999, J MOL BIOL, V293, P917; NR: 20; TC: 0; J9: J CHEM PHYS; PG: 12; GA: 138VLSource type: Electronic(1
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Extensive shad culture
No full textKeywords: Fsh507; Umpqua River; Schofield Creek; Aquaculture; Alosa sapidissima
Ad triangulum. The cathedral of Milan and its dome. From Stornaloco to Bramante, Leonardo and Giovanni Antonio Amadeo
No full textThe construction of the dome of Milan Cathedral represents one of the most fascinating and complex episodes in the history of Italian architecture of the fifteenth century. This is an exemplary case, for the specificity and exceptionality of the Fabbrica del Duomo and for the involvement of some of the most authoritative protagonists of the time - Bramante, Francesco di Giorgio Martini, Luca Fancelli and Leonardo da Vinci - invited by Giangaleazzo and Ludovico Maria Sforza to propose an innovative structural, constructive and formal solution. The desire of the ducal family to assert its image through this enterprise is the backdrop to the succession of builders, workers and ambitious projects committed to giving the building the right crowning glory. The complex story is traced here starting from the recognition of the importance of the intervention of the mathematician from Piacenza Gabriele Stornaloco, creator in 1391 of a geometric scheme to establish the dimensions of the elevation, to be considered the "Ariadne's thread" for the construction of the whole cathedral. Deepening the heated discussion on the adoption of different construction techniques - Lombard, Tuscan and transalpine - the numerous projects proposed to solve the problem of the dome, which pushes the Sforza and the Fabbrica to make use of prestigious consultancy, are then analyzed, also involving Leonardo da Vinci, author of a lost wooden model. Finally we come to the winning project of two Lombards, Giovanni Antonio Amedeo and Giangiacomo Dolcebuono who, between 1490 and 1500, built the dome up to the base of the lantern, using practices rooted in Lombard architectural culture, leaving out only the largest spire that will be built in 1769 as evidence of the complexity of a construction site that lasted over 400 years, making Milan Cathedral one of the most original architecture in Europe
Toward atomic-scale doping of bismuth in silicon: the study of bismuth precursor molecules on silicon (100)
No full textSingle-atom dopants in silicon have been a topic of high interest since the Kane quantum computer was first proposed in 1998. Much work has since been dedicated toward the single-atom doping of lighter group 15 atoms into silicon with atomic-scale precision, with notable success, though significantly less toward heavier dopant atoms owing to the lack of readily available precursor molecules. This thesis investigates two novel potential precursor molecules for atomic bismuth: triphenylbismuth (TPB) and bismuth trichloride (BiCl3). Bismuth is a promising heavy dopant species in silicon-based electronic devices thanks to its high quantum information storage capacity, but currently lacks a suitable precursor. Neither of these molecules has previously been studied on the Si(100) surface.
Using scanning tunnelling microscopy (STM) and X-ray photoelectron spectroscopy (XPS), we demonstrate that TPB partially dissociates on Si(100) at room temperature, with bismuth atoms forming ad-dimers while phenyl remains on the surface. Annealing the surface causes complete molecular dissociation, followed by bismuth diffusion into the bulk. Phenyl desorption is not observed. We show that prior to dissociation, TPB bonds to the surface in a variety of configurations; using density functional theory calculations, we propose favorable bonding structures for the TPB molecule on Si(100).
We also show that BiCl3, contrastingly, undergoes complete and spontaneous dissociation on Si(100) at room temperature, with some bismuth atoms forming ad-dimers while others remain as monomers constrained by adjacent chlorine atoms. We pro- pose key steps in the reaction pathway for room-temperature BiCl3 dissociation. We also demonstrate the molecule’s post-dissociation chemical behavior on Si(100) at higher temperatures, at varying levels of surface coverage. Our results demonstrate that BiCl3 is a promising candidate for a single-atom bismuth precursor, while TPB is less likely to be suitable. In combination with chlorine lithography, this paves the way for single-atom doping of bismuth in silicon devices
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