ComTax: community-driven curation for taxonomic databases

This poster presents the work of the ComTax project to develop a community-driven curation process among practicing scientists and citizen scientists. The project provides tools to help scientists identify and validate appropriate taxonomic names from the scanned historical literature. The system operates on scanned documents, typically taken from the Biodiversity Heritage Library, although documents sourced from other repositories could be used. The system is intended to be used on uncorrected text after optical character recognition (OCR) on the scanned images. The key stages are: 1. Identify possible taxonomic names in the scanned text using machine learning techniques. 2. Verify the extracted names against existing databases. If present, the source scanned text can be automatically marked-up with the name. 3. Unverified names might mean they are not currently recorded in the verification databases, typically because the old name in the literature has been reclassified, or because erroneous OCR means that the name is incorrectly transcribed in the scanned text. In either case: 3.1. Present the proposed name to domain experts or citizen scientists for validation or correction, potentially through a voting mechanism to collect expert judgments on the putative taxonomic name. 3.2. Mark-up the scanned text with the corrected spelling of the name and offer validated taxonomic names for further use by the community. This poster will describe the technical challenges facing the ComTax project, and highlight potential extensions of the work to the curation of other entities of interest in the legacy literature or of different disciplines

What’s in a Name: Gamifying the Intangible History of Larochette, Luxembourg

The Larochette app is part of a larger interdisciplinary project to create a digital reconstruction of the town and castle of Larochette, Luxembourg. The paper discusses the creation of an app that serves to pique interest in linguistics and historical geography, traditionally dry subjects with little intrinsic appeal to children and the general public. This project harnesses this effect, presenting the results of the preceding landscape study in an interactive educational environment that rewards the user for engaging with the content. As the app allows natural movement and intuitive interaction, exploration and learning are prompted by curiosity. The goal of connecting place names to heritage is not explicitly stated, nor is it presented as an educational game. In short, this is the second phase of a collaborative case study in the digital experience of history, which is grounded in user experience design and informed by the historical and architectural expertise of the collaborators

Elastic response of a nematic liquid crystal to an immersed nanowire

We study the immersion of a ferromagnetic nanowire within a nematic liquid crystal using a lattice Boltzmann algorithm to solve the full three-dimensional equations of hydrodynamics. We present an algorithm for including a moving boundary, to simulate a nanowire, in a lattice Boltzmann simulation. The nematic imposes a torque on a wire that increases linearly with the angle between the wire and the equilibrium direction of the director field. By rotation of these nanowires, one can determine the elastic constants of the nematic.Comment: 10 pages, 8 figure

An interacting quark-diquark model of baryons

A simple quark-diquark model of baryons with direct and exchange interactions is constructed. Spectrum and form factors are calculated and compared with experimental data. Advantages and disadvantages of the model are discussed.Comment: 13 pages, 3 eps-figures, accepted by Phys.Rev. C Rapid Communication

A characterization of fine words over a finite alphabet

To any infinite word w over a finite alphabet A we can associate two infinite words min(w) and max(w) such that any prefix of min(w) (resp. max(w)) is the lexicographically smallest (resp. greatest) amongst the factors of w of the same length. We say that an infinite word w over A is "fine" if there exists an infinite word u such that, for any lexicographic order, min(w) = au where a = min(A). In this paper, we characterize fine words; specifically, we prove that an infinite word w is fine if and only if w is either a "strict episturmian word" or a strict "skew episturmian word''. This characterization generalizes a recent result of G. Pirillo, who proved that a fine word over a 2-letter alphabet is either an (aperiodic) Sturmian word, or an ultimately periodic (but not periodic) infinite word, all of whose factors are (finite) Sturmian.Comment: 16 pages; presented at the conference on "Combinatorics, Automata and Number Theory", Liege, Belgium, May 8-19, 2006 (to appear in a special issue of Theoretical Computer Science

Exact closed-form solutions of the Dirac equation with a scalar exponential potential

The problem of a fermion subject to a general scalar potential in a two-dimensional world for nonzero eigenenergies is mapped into a Sturm-Liouville problem for the upper component of the Dirac spinor. In the specific circumstance of an exponential potential, we have an effective Morse potential which reveals itself as an essentially relativistic problem. Exact bound solutions are found in closed form for this problem. The behaviour of the upper and lower components of the Dirac spinor is discussed in detail, particularly the existence of zero modes.Comment: 16 pages, 3 figure

Force-extension relation of cross-linked anisotropic polymer networks

Cross-linked polymer networks with orientational order constitute a wide class of soft materials and are relevant to biological systems (e.g., F-actin bundles). We analytically study the nonlinear force-extension relation of an array of parallel-aligned, strongly stretched semiflexible polymers with random cross-links. In the strong stretching limit, the effect of the cross-links is purely entropic, independent of the bending rigidity of the chains. Cross-links enhance the differential stretching stiffness of the bundle. For hard cross-links, the cross-link contribution to the force-extension relation scales inversely proportional to the force. Its dependence on the cross-link density, close to the gelation transition, is the same as that of the shear modulus. The qualitative behavior is captured by a toy model of two chains with a single cross-link in the middle.Comment: 7 pages, 4 figure

Bounded solutions of neutral fermions with a screened Coulomb potential

The intrinsically relativistic problem of a fermion subject to a pseudoscalar screened Coulomb plus a uniform background potential in two-dimensional space-time is mapped into a Sturm-Liouville. This mapping gives rise to an effective Morse-like potential and exact bounded solutions are found. It is shown that the uniform background potential determinates the number of bound-state solutions. The behaviour of the eigenenergies as well as of the upper and lower components of the Dirac spinor corresponding to bounded solutions is discussed in detail and some unusual results are revealed. An apparent paradox concerning the uncertainty principle is solved by recurring to the concepts of effective mass and effective Compton wavelength.Comment: 15 pages, 7 figure