322,983 research outputs found
A semi-flexible model prediction for the polymerization force exerted by a living F-actin filament on a fixed wall
No full textWe consider a single living semi-flexible filament with persistence length ℓp in chemical equilibrium with a solution of free monomers at fixed monomer chemical potential μ1 and fixed temperature T. While one end of the filament is chemically active with single monomer (de)polymerization steps, the other end is grafted normally to a rigid wall to mimic a rigid network from which the filament under consideration emerges. A second rigid wall, parallel to the grafting wall, is fixed at distance L < < ℓp from the filament seed. In supercritical conditions where monomer density ρ1 is higher than the critical density ρ1c, the filament tends to polymerize and impinges onto the second surface which, in suitable conditions (non-escaping filament regime), stops the filament growth. We first establish the grand-potential Ω(μ1, T, L) of this system treated as an ideal reactive mixture, and derive some general properties, in particular the filament size distribution and the force exerted by the living filament on the obstacle wall. We apply this formalism to the semi-flexible, living, discrete Wormlike chain model with step size d and persistence length ℓp, hitting a hard wall. Explicit properties require the computation of the mean force f i (L) exerted by the wall at L and associated potential f i (L) = - d W i (L) / d L on a filament of fixed size i. By original Monte-Carlo calculations for few filament lengths in a wide range of compression, we justify the use of the weak bending universal expressions of Gholami et al. [Phys. Rev. E 74, 041803 (2006)] over the whole non-escaping filament regime. For a filament of size i with contour length Lc = (i - 1) d, this universal form is rapidly growing from zero (non-compression state) to the buckling value f b (L c, ℓ p) = π 2 k B T ℓ p 4 L c 2 over a compression range much narrower than the size d of a monomer. Employing this universal form for living filaments, we find that the average force exerted by a living filament on a wall at distance L is in practice L independent and very close to the value of the stalling force F s H = (k B T / d) ln (ρ 1) predicted by Hill, this expression being strictly valid in the rigid filament limit. The average filament force results from the product of the cumulative size fraction x = x (L, ℓ p, ρ 1), where the filament is in contact with the wall, times the buckling force on a filament of size Lc ≈ L, namely, F s H = x f b (L; ℓ p). The observed L independence of F s H implies that x ∝ L-2 for given (ℓ p, ρ 1) and x ∝ ln ρ 1 for given (ℓp, L). At fixed (L, ρ 1), one also has x ∝ ℓ p - 1 which indicates that the rigid filament limit ℓp → ∞ is a singular limit in which an infinite force has zero weight. Finally, we derive the physically relevant threshold for filament escaping in the case of actin filaments.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Diffusive author(s), cohesive author: Analysis of S/N (1994)
No full textThis study indicates the ways in which various aspects of the author(s) are brought forth in Dumb type’s performance art, the S/N production. Previous research has suggested a non-hierarchical organization of Dumb type and the absence of a “privileged author” in Dumb type’s collaborative work, S/N. However, the results that I have investigated from member’s interviews on the creative process of S/N along with my analysis of the recorded images of S/N, indicate a different aspect of the author(s). First, S/N was created through, so to speak, the collective ideas of the members of Dumb type. Further, S/N has at least nine quotations from previous performances, installations, and printed writings, besides the work-in-progress technique. Explicating one of the “author functions” as given by Michel Foucault, each text has plural subjects of the author. However, it has been revealed from members’ interviews that Teiji Furuhashi had a decision-making role in selecting the members’ ideas within the performance. Since then, S/N has had plural subjects of creation; however, Furuhashi is one of the subjects of creation along with the “privileged author.” S/N has plural authors (diffusive authors) yet at the same time, it has a “privileged author,” Teiji Furuhashi (cohesive author)
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Bartoli de Saxoferrato Prima [-secunda] svper digesto novo. Inest hvic volumini commentariorvm [...] in digestu[m] nouum pars prima [-Secunda] unà cum scholijs complurium clarissimorum uirorum, doctis, elimatis, & mire profuturis [...].
No full textPlaats en drukker uit colofonHerkomst: Mon.rij S. Petri in Blandino iuxta Gandavum [Sint-Pietersabdij Gent]Machiels, J. Catalogus van de boeken gedrukt vóór 1600 ; B 154Band: 16e eeuws, leder op hout, ruitverdeling met losse blindstempels, in hoeken initialen IR (Jan Ryckaert); schutbladen: handschrift in Latijn op perkament (Commentaar op Romeins recht, 14e eeuw), slotspore
Aureus & in practica perutilis totus & singularis tractatus feudorum /
No full textDrukkersmerk op titelbladImpressum uit colofon: f. E10r: die xxx. me[n]sis MarcijIncipit [...] Tractatus de homagijs [...] f. AA1rHerkomst: Sacri mon.rij S. Petri in Blandinio iuxta Gandavum 1598 [Sint-Pietersabdij Gent]Band: Leder op hout, gesigneerde band van I. R. (Jan Ryckaert), Latijns handschrift op de schutbladen (Commentaar op Romeins recht, 14e eeuw)Machiels, J. Catalogus van de boeken gedrukt vóór 1600 ; S 10
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Design strategy for layout of Sub-Resolution Directed Self-Assembly Assist Features (SDRAFs)
No full textAnnotationes Gulielmi Budæi [...] in quatuor & viginti Pandectarum libros, ad Ioannem Deganaium cancellarium Franciæ.
No full textColofon: Excvdebat ... calendis Septemb.Drukkersmerk op titelbladHerkomst: Sum monasterij S. Petri Blandiniensis iuxta Gandavum [Sint-Pietersabdij Gent]Kalfslederen band op hout. In ruiten verdeeld middenveld waarin losse stempels (herder, ruiker, lelie, vlieg). Errond een fries (herder, roos) met op de 4 hoeken initialen I R (Jan Ryckaert). Slotsporen. Rug later hersteld. Schutbladen: Latijns handschrift (Epistolae Hieronymus, 14e eeuw)Machiels, J. Catalogus van de boeken gedrukt vóór 1600 ; B 1052Schatten van de universiteitsbibliotheek II. - Gent : RUG. Centrale bibliotheek, 1968. - p. 8-9Europeana-GoogleBook
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