On the isolation of TI-plasmid from Agrobacterium tumefaciens

An efficient lysis method for Agrobacterium cells was developed, which allows a reproducible isolation of the tumor inducing (TI)-plasmid. The lysis method is based on the sensitivity of this bacterium to incubation with lysozyme, n-dodecylamine,EDTA, followed by Sarkosyl, after growth in the presence of carbenicillin. We also present a procedure for the isolation of the TI-plasmid on a large scale, that might be used for the mass isolation of other large plasmids which like the TI-plasmid, can not be cleared with earlier described procedures. The purity of the plasmid preparations was determined with DNA renaturation kinetics, which method has the advantage that the plasmid need not to be in the supercoiled or open circular form

Unification and Grammatical Theory

This paper informally presents a new view of grammar that has emerged from a number of distinct but related lines of investigation in theoretical and computational linguistics. Under this view, many current linguistic theories—-including Lexical-Functional Grammar (LFG), Generalized Phrase Structure Grammar (GPSG), Head-Driven Phrase Structure Grammar (HPSG), and categorial grammar (CG)—-fall within a general framework of unification grammar. In such theories the linguistic objects under study are associated with linguistic information about the objects, which information is modeled by mathematical objects called feature structures. Linguistic phenomena are modeled by constraints of equality over the feature structures; the fundamental operation upon the feature structures, allowing solution of such systems of equations, is a simple merging of their information content called unification. Although differences among these theories remain great, this new appreciation of the common threads in research paradigms previously thought ideologically incompatible provides an opportunity for a uniting of efforts and results among these areas, as well as the ability to compare previously incommensurate claims.Engineering and Applied Science

Automatic Acquisition of Ranked Qualia Structures from the Web

Cimiano P, Wenderoth J. Automatic Acquisition of Ranked Qualia Structures from the Web. In: Carroll JA, van den Bosch A, Zaenen A, eds. ACL 2007, Proceedings of the 45th Annual Meeting of the Association for Computational Linguistics. 2007: 888-895

A basic logic for textual inference

This note describes a logical system based on ¡£ ¢ concepts ¤ and contexts, the system for textual inference ¡£ ¢ ¤ logic. The system is the beginnings of a logic that is a kind of “contexted” description logic, designed to support local linguistic inferences. This logic pays attention to the intensionality of linguistic constructs and to the need for tractability of inference in knowledge representation formalisms

Textual inference logic: Take two

Abstract. This note describes a logical system based on concepts and contexts, whose aim is to serve as a representation language for meanings of natural language sentences. The logic is a theoretical description of the output of an evolving implemented system, the system Bridge, which we are developing at parc, as part of the aquaint program. The note concentrates on the results of an experiment which changed the underlying ontology of the representation language from cyc to a version of WordNet/VerbNet.