Coordination using a Single-Writer Multiple-Reader Concurrent Logic Language

The principle behind concurrent logic programming is a set of processes which co-operate in monotonically constraining a global set of variables to particular values. Each process will have access to only some of the variables, and a process may bind a variable to a tuple containing further variables which may be bound later by other processes. This is a suitable model for a coordination language. In this paper we describe a type system which ensures the co-operation principle is never breached, and which makes clear through syntax the pattern of data flow in a concurrent logic program. This overcomes problems previously associated with the practical use of concurrent logic languages

Are ethnicity, social grade, and social deprivation associated with severity of thyroid-associated ophthalmopathy?

PURPOSE: Previous studies have extensively investigated the pathophysiology, genetics, and lifestyle risk factors of thyroid-associated ophthalmopathy (TAO). The aim of this study was to investigate the independent contribution of ethnic origin, social grade, and level of social deprivation to TAO severity in a large, multiethnic, and urban population. METHODS: Retrospective case note review of all TAO patients seen at Birmingham and Midland Eye Centre, United Kingdom over a 14-year period. Ethnicity (White, Asian, or Black) was recorded, and residence postcode was used to determine social grade (National Readership Survey classification) and level of social deprivation (Index of Multiple Deprivation 2007). TAO severity was defined by European Group on Graves’ Orbitopathy criteria. Moderate-to-severe: necessity for TAO treatment with oral or intravenous steroid, long-term immunosuppressants, or orbital radiotherapy. Sight-threatening: presence of dysthyroid optic neuropathy (DON) or need for urgent orbital decompression surgery. Multivariable logistic regression was performed to measure the independent influence of ethnicity, social grade, and social deprivation on indicators of severe TAO. RESULTS: Lower social grade was significantly associated with increased odds ratio (OR) of TAO patients having severe TAO, including treatment with oral (OR: 2.3 (95% CI 1.1–5.1) p = 0.03) and intravenous steroid (OR: 2.6 (95% CI 1.0–7.0) p = 0.04) and DON (OR: 4.0 (95% CI 1.2–12.7) p = 0.02), compared with those of highest social grade. Similar results were observed for social deprivation. Ethnicity had no independent association with any measure of TAO severity. CONCLUSIONS: In this cohort, lower social grade and higher social deprivation, but not ethnicity, had independent, statistically significant association with more severe TAO

Programming in concurrent logic languages

Coordination using a Single-Writer Multiple-Reade

Search In Concurrent Logic Languages

Starting from a simple declarative all-solutions program, we develop a variety of search programs in the concurrent logic language RGDC [Cohen et al 92], leading up to a full heuristics-guided parallel version of branch-and-bound search. Our programs are general enough to be useable in a variety of problems in artificial intelligence, operations research and logic metaprogramming. We aim to meet the criticism that concurrent logic languages are unsuitable for programming search problems, and counter-argue that their removal of automated backtracking is in fact a desirable feature. This calls into question whether the development of "portmanteau " logic programming languages which attempt to combine features from Prolog and the committed choice logic languages is the best way for logic programming to develop, when the power of these features could equally be provided by the development of programming techniques in committed choice logic languages. BACKTRACKING CONSIDERED HARMFUL? The c..