Although South America lost more megafaunal genera than any other continent during the Late-Quaternary Extinction event (LQE), little is known about the chronology, causes or dynamics of these extinctions, especially in the northern part of the continent. Fossil deposits in…

Background: Clinical examinations increasingly consist of composite tests to assess all aspects of the curriculum recommended by the General Medical Council.
Setting: A final undergraduate medical school examination for 214 students.
Aim: To estimate the overall reliability of a composite…

The chemical composition of the essential oils from leaves and stems of Eugenia sulcata Spring ex Mart., obtained by hydrodistillation, was analyzed by GC-MS and quantified by CG-FID. In all, 37 components were identified and sesquiterpenes represented the largest fraction…

This paper presents a proposal for an architecture that integrates knowledge discovery systems (automatic acquisition) and knowledge based systems (experts systems). This work formulates considerations over the viability of the implementation of this architecture according to the advance of the…

This paper aims to clarify an economic mechanism behind the growing dichotomy between geo-economics and the borderless global knowledge economy. The proposed hypothesis is that geo-economic fault-lines, which are the product of the past prejudices of racial, linguistic, and cultural…

The Semantic Web attempts to reach a state in the future where everything on the Web will no longer be only machine-readable, but also machine-understandable. An ontology is an explicit specification of a conceptualization. A conceptualization is an abstract, simplified…

Collaborative systems are becoming a widely used tool particularly among professional communities and research groups. They provide a suitable context for distributed people working on the same subject to concentrate their work in a shared place to which everyone has…

In this paper, we present an approach to student's evaluation in a well-defined domain based on a semantic network. A similarity matrix based on the semantic memory structure of humans is used to build a semantic distance model in order…

In this work we analyze the problem of knowledge representation in a collaborative multi-agent system where agents can obtain new information from others through communication. Namely, we analyze several approaches of belief revision in multi-agent systems. We will describe different…

Tardigrades constitute one of three clades of Xenarthra. Whereas modern tree sloths are common in the Amazonian Basin, their giant ground sloth "kin" were abundant throughout the Americas. During the Miocene, sloths were conspicuous faunal elements in Patagonia, generally considered…