On the equivalence between logic programming semantics and argumentation semantics

This work has been supported by the National Research Fund, Luxembourg (LAAMI project), by the Engineering and Physical Sciences Research Council (EPSRC, UK), grant Ref. EP/J012084/1 (SAsSy project), by CNPq (Universal 2012 – Proc. 473110/2012-1), and by CNPq/CAPES (Casadinho/PROCAD 2011).Peer reviewedPreprin

On the Equivalence between Logic Programming Semantics and Argumentation Semantics

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On the Difference between Assumption-Based Argumentation and Abstract Argumentation

Acknowledgements The first author has been supported by the National Research Fund, Luxembourg (LAAMI project) and by the Engineering and Physical Sciences Research Council (EPSRC, UK), grant ref. EP/J012084/1 (SAsSy project). The second and third authors have been supported by CNPq (Universal 2012 - Proc. no. 473110/2012-1), CAPES (PROCAD 2009) and CNPq/CAPES (Casadinho/PROCAD 2011).Peer reviewedPostprin

On the Difference between Assumption-Based Argumentation and Abstract Argumentation

Preprin

On the difference between assumption-based argumentation and abstract argumentation

In the current paper, we re-examine the connection between abstract argumentation and assumption-based argumentation. These two formalisms are often claimed to be equivalent in the sense that (a) evaluating an assumption based argumentation framework directly with the dedicated semantics, and (b) first constructing the corresponding abstract argumentation framework and then applying the corresponding abstract argumentation semantics, produce the same outcome. Although this holds for several semantics, in this work we show that there exist well-studied admissibility-based semantics (semi-stable and eager) under which equivalence does not hold

Online Handbook of Argumentation for AI: Volume 1

This volume contains revised versions of the papers selected for the first volume of the Online Handbook of Argumentation for AI (OHAAI). Previously, formal theories of argument and argument interaction have been proposed and studied, and this has led to the more recent study of computational models of argument. Argumentation, as a field within artificial intelligence (AI), is highly relevant for researchers interested in symbolic representations of knowledge and defeasible reasoning. The purpose of this handbook is to provide an open access and curated anthology for the argumentation research community. OHAAI is designed to serve as a research hub to keep track of the latest and upcoming PhD-driven research on the theory and application of argumentation in all areas related to AI.Comment: editor: Federico Castagna and Francesca Mosca and Jack Mumford and Stefan Sarkadi and Andreas Xydi

High Prevalence of the Amphibian Chytrid Fungus (\u3cem\u3eBatrachochytrium dendrobatidis\u3c/em\u3e) across Multiple Taxa and Localities in the Highlands of Ethiopia

Surveys of the potentially lethal amphibian chytrid fungus (Batrachochytrium dendrobatidis - Bd) in Africa are patchy, especially in some regions of high species endemicity. We present results of the first Bd surveys of wild amphibians in Ethiopia, for two upland regions on either side of the Rift Valley: the Bale Mountains and the Kaffa region. Surveys were opportunistic so that robust interpretation of the data is limited. Utilizing diagnostic qPCR assays, 51 out of 120 frogs (14 species in 10 genera) tested positive for Bd at altitudes of 1,620–3,225 m, across all genera and species, and all but two localities. Prevalence was not significantly different between the two regions or two years (2008, 2009) sampled. Prevalence and parasite load was higher in species with aquatic tadpoles than those with terrestrial early life-history stages, but these differences were not significant. Impacts of Bd infection were not investigated, but no dead or dying frogs were found. This is the first report of Bd in Ethiopia, a country in which approximately 40% of its more than 60 species are endemic. Declines have occurred in some frog species in some localities in Ethiopia, and although habitat degradation is a likely cause in at least some places, further studies of Bd in Ethiopia are required to understand if it is a threat

Evolutionary Relationships of the Critically Endangered Frog \u3cem\u3eEricabatrachus baleensis\u3c/em\u3e Largen, 1991 with Notes on Incorporating Previously Unsampled Taxa into Large-scale Phylogenetic Analyses

Background: The phylogenetic relationships of many taxa remain poorly known because of a lack of appropriate data and/or analyses. Despite substantial recent advances, amphibian phylogeny remains poorly resolved in many instances. The phylogenetic relationships of the Ethiopian endemic monotypic genus Ericabatrachus has been addressed thus far only with phenotypic data and remains contentious. Results: We obtained fresh samples of the now rare and Critically Endangered Ericabatrachus baleensis and generated DNA sequences for two mitochondrial and four nuclear genes. Analyses of these new data using de novo and constrained-tree phylogenetic reconstructions strongly support a close relationship between Ericabatrachus and Petropedetes, and allow us to reject previously proposed alternative hypotheses of a close relationship with cacosternines or Phrynobatrachus. Conclusions: We discuss the implications of our results for the taxonomy, biogeography and conservation of E. baleensis, and suggest a two-tiered approach to the inclusion and analyses of new data in order to assess the phylogenetic relationships of previously unsampled taxa. Such approaches will be important in the future given the increasing availability of relevant mega-alignments and potential framework phylogenies

Long-term data for endemic frog genera reveal potential conservation crisis in the Bale Mountains, Ethiopia

Populations of many frogs have declined alarmingly in recent years, placing nearly one third of the >6,000 species under threat of extinction. Declines have been attributed largely to habitat loss, environmental degradation and/or infectious diseases such as chytridiomycosis. Many frogs undergo dramatic natural population fluctuations such that long-term data are required to determine population trends without undue influence of stochastic factors. We present long-term quantitative data (individuals encountered per person hour of searching) for four monotypic frog genera endemic to an Afromontane region of exceptional importance but growing conservation concern: one endemic to the Ethiopian highlands (Spinophrynoides osgoodi) and three endemic to the Bale Mountains (Altiphrynoides malcolmi, Balebreviceps hillmani, Ericabatrachus baleensis), collected during 15 field trips to the Bale Mountains between 1971 and 2009. Only a single confirmed sighting of S. osgoodi has been made since 1995. The other three species have also declined, at least locally. E. baleensis appears to have been extirpated at its type locality and at the same site B. hillmani has declined. These declines are in association with substantial habitat degradation caused by a growing human population. Chytrid fungus has been found on several frog species in Bale, although no dead or moribund frogs have been encountered. These results expose an urgent need for more amphibian surveys in the Bale Mountains. Additionally, we argue that detrimental human exploitation must be halted immediately in at least some parts of the Harenna Forest if a conservation crisis is to be averte