Physical Coupling Schemes and QCD Exclusive Processes

I discuss application of the BLM method to obtain commensurate scale relations connecting QCD exclusive amplitudes to other observables, in particular the heavy quark potential.Comment: 7 pages, Latex, uses l-school.sty. Talk given at "New Nonperturbative Methods and Quantization on the Light Cone," Les Houches, France, 24 Feb.-7 March 1997. To appear in the proceeding

Declarative Specification

Deriving formal specifications from informal requirements is extremely difficult since one has to overcome the conceptual gap between an application domain and the domain of formal specification methods. To reduce this gap we introduce application-specific specification languages, i.e., graphical and textual notations that can be unambiguously mapped to formal specifications in a logic language. We describe a number of realised approaches based on this idea, and evaluate them with respect to their domain specificity vs. generalit

De Novo Assembly of Nucleotide Sequences in a Compressed Feature Space

Sequencing technologies allow for an in-depth analysis of biological species but the size of the generated datasets introduce a number of analytical challenges. Recently, we demonstrated the application of numerical sequence representations and data transformations for the alignment of short reads to a reference genome. Here, we expand out approach for de novo assembly of short reads. Our results demonstrate that highly compressed data can encapsulate the signal suffi- ciently to accurately assemble reads to big contigs or complete genomes

Potential and historical Uses for bracken (Pteridium aquilinum (L.) Kuhn) in organic agriculture

This report was presented at the UK Organic Research 2002 Conference. Bracken is considered a serious weed species, due to its toxic constituents and negative impacts on agriculture and conservation. Historically however, this fern was a highly prized commodity due to the many uses for cut fronds. Cutting bracken is one of the few bracken management options open to organic farmers. Many traditional uses for the material resulting from harvesting material may have potential in modern organic agriculture, putting a modern value on the plant for its sustainable use or its eradication. This poster reviews some traditional and potential uses within agriculture, investigated as part of a MPhil research project. These uses for bracken include; use as a source of fertility from raw material and ash, weed control for vegetable crops, animal bedding, cover mulch, insect repellent, seed treatment, anti-fungal agent, and biofuel

Groupoid algebras as Cuntz-Pimsner algebras

We show that if $G$ is a second countable locally compact Hausdorff \'etale groupoid carrying a suitable cocycle $c:G\to\mathbb{Z}$, then the reduced $C^*$-algebra of $G$ can be realised naturally as the Cuntz-Pimsner algebra of a correspondence over the reduced $C^*$-algebra of the kernel $G_0$ of $c$. If the full and reduced $C^*$-algebras of $G_0$ coincide, we deduce that the full and reduced $C^*$-algebras of $G$ coincide. We obtain a six-term exact sequence describing the $K$-theory of $C^*_r(G)$ in terms of that of $C^*_r(G_0)$.Comment: 5 pages. V2: James Fletcher discovered an error Lemma 9. No other results are affected. In this version, statements (2) and (3), and the proof, of Lemma 9 have been corrected. Remark 10 has been added to give details of the error. An erratum will appear in Math Scand, referring to this version of the arXiv posting for detail

KMS states on generalised Bunce-Deddens algebras and their Toeplitz extensions

We study the generalised Bunce-Deddens algebras and their Toeplitz extensions constructed by Kribs and Solel from a directed graph and a sequence $\omega$ of positive integers. We describe both of these $C^*$-algebras in terms of novel universal properties, and prove uniqueness theorems for them; if $\omega$ determines an infinite supernatural number, then no aperiodicity hypothesis is needed in our uniqueness theorem for the generalised Bunce-Deddens algebra. We calculate the KMS states for the gauge action in the Toeplitz algebra when the underlying graph is finite. We deduce that the generalised Bunce-Deddens algebra is simple if and only if it supports exactly one KMS state, and this is equivalent to the terms in the sequence $\omega$ all being coprime with the period of the underlying graph.Comment: 30 pages. This version includes a section on the topological graph $E(\infty)$, which allows us to use the work of Katsura to obtain a uniqueness theorem for $C^*(E,\omega)$, and a characterisation of the ideal structure of $C^*(E,\omega)$ when $E$ is finite and strongly connected. The introduction and references have been updated. Minor typos have been correcte