Extraction of tidal channel networks from airborne scanning laser altimetry and aerial photography

The study of the morphodynamics of tidal channel networks is important because of their role in tidal propagation and the evolution of salt-marshes and tidal flats. Channel dimensions range from tens of metres wide and metres deep near the low water mark to only 20-30cm wide and 20cm deep for the smallest channels on the marshes. The conventional method of measuring the networks is cumbersome, involving manual digitising of aerial photographs. This paper describes a semi-automatic knowledge-based network extraction method that is being implemented to work using airborne scanning laser altimetry (and later aerial photography). The channels exhibit a width variation of several orders of magnitude, making an approach based on multi-scale line detection difficult. The processing therefore uses multi-scale edge detection to detect channel edges, then associates adjacent anti-parallel edges together to form channels using a distance-with-destination transform. Breaks in the networks are repaired by extending channel ends in the direction of their ends to join with nearby channels, using domain knowledge that flow paths should proceed downhill and that any network fragment should be joined to a nearby fragment so as to connect eventually to the open sea.

Voice, body and the transmission of the real in documentary theatre

This article analyses how listening is used to develop performances in Alecky Blythe’s verbatim theatre. Listening includes Blythe’s use of recorded oral interviews for devising performances, and also the actors’ creation of performance by precisely imitating an interviewee’s voice. The article focuses on listening, speaking and embodiment in London Road, Blythe’s recent musical play at London’s National Theatre, which adopted and modified theatre strategies used in her other plays, especially The Girlfriend Experience and Do We look Like Refugees. The article draws on interviews with performers and with Blythe herself, in its critical analysis of how voice legitimates claims to authenticity in performance. The work on Blythe is contextualised by brief comparative analyses. One is Clio Barnard’s film The Arbor, a ‘quasi-documentary’ on the playwright, Andrea Dunbar which makes use of an oral script to which the actors lip-sync. The other comparator is the Wooster Group’s Poor Theater, which attempts to recreate Grotowski's Akropolis via vocal impersonation. The article argues that voice in London Road both claims and defers authenticity and authority, inasmuch as voice signifies presence and embodied identity but the reworking of speech into song signals the absence of the real. The translation of voice into written surtitles works similarly in Do We Look Like Refugees. Blythe’s theatre, Barnard’s film and The Wooster Group’s performances are a useful framework for addressing questions of voice and identity, and authenticity and replication in documentary theatre. The article concludes by placing Blythe’s oral texts amid current debates around theatre’s textual practices.

Literal and extended use of kinship terms in documentary papryi

Kinship terms in papyrus letters do not always refer to actual relatives and so pose many problems for modern readers. But by examining all the kinship terms in six centuries of letters it is possible to discover some rules governing the use of kinship terms: in some situations they appear to be always literal, and in others they appear to be almost always extended, though a third group of contexts remains ambiguous. The rules are complex and depend on the particular kinship term involved, the date of writing, the use of names, the position of the kinship term in the letter, and the person to whom it connects the referent.