The concept of free as in "free group" is generalized to any first order theory. An interesting class of homomorphisms between models is discussed. Relations between model theory and abelian categories are discussed speculatively. This paper represents an incomplete study…

A program, some TECO macros, and some small modifications to existing systems software have been written, called PRO, whose purpose is to reduce the large number of control languages and system programs it has been necessary to know about and…

This paper demonstrates that it is possible to generate a reasonably accurate coordinate system on randomly distributed processors, using only local information and local communication. By coordinate systems we imply that each element assigns itself a logical coordinate that maps…

The objectives of this work were: (i) identified the risk areas of landslides, flooding and sea level rise and social vulnerabilities in different scales of analysis; (ii) analyse the risk perception of people living in this risk areas; (iii) found…

O presente trabalho relata a experiência desenvolvimento e aplicação, no âmbito de um projeto de pesquisa, de um modelo de organização e representação do conhecimento sobre os processos de intensificação agropecuária, contextualizados por observações empíricas em regiões produtoras de commodities…

A notable contribution to the knowledge of relative incidence and cause of mortality in pigs was made by an extensive survey carried out by the Ministry of Agriculture, Fisheries and Food, Veterinary Investigation Service in England. [...]

En los crustáceos decápodos, las proteasas digestivas más comúnmente descritas son de la clase serino, sin embargo, estudios recientes reportan la presencia de otras clases de enzimas como las cisteíno proteasas en especies de decápodos Carideos y más recientemente proteasas…

The following information, as revealed in these studies, is claimed to be a contribution to knowledge. A bacterium and a fungus identified as a Pseudomonas sp. and a Penicillium sp. were isolated by the soil perfusion enrichment technique, and are…

Chemical reactions involve ordinarily the breaking of bonds in the reacting molecules and the formation of bonds in the products; they are usually accompanied by changes in enthalpy. Although the stability of a molecule or a radical, as expressed in…

The aim of Historical Geography is essentially twofold - the elucidation of the present geographical reality of an area by the fuller understanding of its past development, and the attainment of some knowledge of the processes of geographical change. Most…