We show that the intersection of the class of 2-REA degrees with that of the !-r.e. degrees consists precisely of the class of d.r.e. degrees. We also include some applications and show that there is no natural generalization of this result to higher levels of the REA hierarchy.

S higella infection is the least common of the gastroenteritis-inducing organisms which are associated with reactive arthritis (ReA) in developed countries, reflecting the scarcity of the organism in these environments. A recent thorough survey of Shigella infected subjects in Finland describes an annual incidence of Shigella induced ReA of only 1.3 per million. This compares with the incidence...

Encryption in database systems is an important topic for research, as secure and efficient algorithms are needed that provide the ability to query over encrypted database and allow optimized encryption and decryption of data. Clearly, there is a compromise between the degree of security provided by encryption and the efficient querying of the database, because the operations of encryption and d...

The outer membrane protein (OMP) composition (OMP typing) of 46 fecal Aeromonas strains from hybridization groups (HGs) 1 (A. hydrophila; n = 10), 4 (A. caviae; n = 16), and 8 (A. veronii; n = 20) were examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis as a phenotypic typing method. Almost every isolate of HG-1 and HG-8 had a unique OMP profile, in contrast to isolates of HG-...

This paper describes the gradual formation of the metamodel of the REA model level of the REA enterprise ontology. The paper aims to create a basic structure that allows creating valid models of the ontology. The first part of the paper discusses the identification of the elements used as a basis for the metamodel and their relationships. The second part describes the creation of the metamodel ...

The implementation of a domain agnostic software system (such as an enterprise resource planning system or a trading information system) based on the REA model requires a generic, yet highly adaptable software architecture. Building on top of well established academic findings and proposals regarding the REA model we are proposing a software model building on two main concepts: fragments and de...

Most juridical systems contain the principle that an act is only unlawful if the agent conducting the act has a `guilty mind' (`mens rea'). Different law systems distinguish di erent modes of mens rea. For instance, American law distinguishes between `knowingly' performing a criminal act, `recklessness', `strict liability', etc. I will show we can formalize several of these categories. The form...

The complexity of service systems has raised interest in developing ontologies that contribute to the conceptual clarification of value co-creation activities and that eventually serve as knowledge representations for systems exploiting reasoning and inference on those ontologies for various practical purposes. The Resource-Event-Agent (REA) enterprise ontology shares similar aims even though i...

The extent of synovial cell proliferation in situ and its relationship to the destructive potential of rheumatoid arthritis (RA) is a matter of continuing debate. Notably, the situation has not been elucidated in other inflammatory arthritides [i.e. reactive (ReA) and psoriatic (PsA)], which, although they share some histopathological similarities with RA, develop different patterns of joint in...

The regular extension axiom, REA, was first considered by Peter Aczel in the context of Constructive Zermelo-Fraenkel Set Theory as an axiom that ensures the existence of many inductively defined sets. REA has several natural variants. In this note we gather together metamathematical results about these variants from the point of view of both classical and constructive set theory. MSC:03F50, 03F35