Towards an abstract characterization of the subargument relation

Dung’s classic framework is formed by abstract arguments and a binary relation denoting attacks between arguments. Several semantic elaboration and extensions based on this framework are present in the literature. The notion of subargument, however, was not widely studied as an abstract concept although it is an important part of fully implemented argument systems. In this paper we introduce the characterization of properties of a sensible subargument relation in abstract argumentation frameworksWorkshop de Agentes y Sistemas Inteligentes (WASI)Red de Universidades con Carreras en Informática (RedUNCI

Towards an abstract characterization of the subargument relation

Dung’s classic framework is formed by abstract arguments and a binary relation denoting attacks between arguments. Several semantic elaboration and extensions based on this framework are present in the literature. The notion of subargument, however, was not widely studied as an abstract concept although it is an important part of fully implemented argument systems. In this paper we introduce the characterization of properties of a sensible subargument relation in abstract argumentation frameworksWorkshop de Agentes y Sistemas Inteligentes (WASI)Red de Universidades con Carreras en Informática (RedUNCI

Vientos MHD anisótropos

La anisotropía en los vientos estelares suele introducirse a través de un parámetro de asimetría de masa, manteniendo esféricas las superficies alfvénicas. Sin embargo, mas allá de cierta simplificación matemática que este procedimiento implica, el formalismo presenta algunas características que merecen ser revisadas. En este trabajo se cambia el enfoque tradicional, introduciendo la anisotropía a través de la función de Mach-Alfvén y no del perfil de densidad de masa. A modo de ilustración se resuelve el problema de un viento embebido en un campo puramente radial. Los resultados obtenidos se discuten a la luz de las observaciones y de la estabilidad de los modelos.Asociación Argentina de Astronomí

Towards an abstract characterization of the subargument relation

Dung’s classic framework is formed by abstract arguments and a binary relation denoting attacks between arguments. Several semantic elaboration and extensions based on this framework are present in the literature. The notion of subargument, however, was not widely studied as an abstract concept although it is an important part of fully implemented argument systems. In this paper we introduce the characterization of properties of a sensible subargument relation in abstract argumentation frameworksWorkshop de Agentes y Sistemas Inteligentes (WASI)Red de Universidades con Carreras en Informática (RedUNCI

Augmented intracellular glutathione inhibits fas-triggered apoptosis of activated human neutrophils

Q1Q1Agonist signals delivered through cell surface Fas induce apoptosis. However, the apoptotic program can be modulated by signals from the environment, and in particular, by signals delivered through adhesion molecules. Because neutrophil functional activity in inflammation is contingent on cell survival, and because circulating neutrophils normally die rapidly through a constitutively expressed apoptotic program, we evaluated Fas-mediated apoptosis in resting and inflammatory human neutrophils. We show that normal neutrophils respond to Fas engagement with accelerated rates of apoptosis, but cross-linking of β2 integrins or priming with bacterial lipopolysaccharide (LPS) prevents this increase. Adhesion molecule cross-linking results in increased intracellular glutathione (GSH). Augmentation of intracellular GSH with exogenous GSH or N-acetylcysteine is sufficient to reduce the Fas-triggered increase in apoptotic rates. Prevention of the activation induced GSH increase by buthionine sulfoximine, a cell permeable inhibitor of GSH biosynthesis, restored Fas responsiveness in activated neutrophils, an effect that could be blocked with exogenous GSH. Taken together, these data show that Fas-induced signaling for neutrophil apoptosis is blocked in a redox sensitive manner by costimulatory signals delivered through β2 integrins or activation by LPS, and provide a biologic explanation for sustained neutrophil survival in the inflammatory environment.Revista Nacional - Indexad

Coral Disease and Health Workshop: Coral Histopathology II

The health and continued existence of coral reef ecosystems are threatened by an increasing array of environmental and anthropogenic impacts. Coral disease is one of the prominent causes of increased mortality among reefs globally, particularly in the Caribbean. Although over 40 different coral diseases and syndromes have been reported worldwide, only a few etiological agents have been confirmed; most pathogens remain unknown and the dynamics of disease transmission, pathogenicity and mortality are not understood. Causal relationships have been documented for only a few of the coral diseases, while new syndromes continue to emerge. Extensive field observations by coral biologists have provided substantial documentation of a plethora of new pathologies, but our understanding, however, has been limited to descriptions of gross lesions with names reflecting these observations (e.g., black band, white band, dark spot). To determine etiology, we must equip coral diseases scientists with basic biomedical knowledge and specialized training in areas such as histology, cell biology and pathology. Only through combining descriptive science with mechanistic science and employing the synthesis epizootiology provides will we be able to gain insight into causation and become equipped to handle the pending crisis. One of the critical challenges faced by coral disease researchers is to establish a framework to systematically study coral pathologies drawing from the field of diagnostic medicine and pathology and using generally accepted nomenclature. This process began in April 2004, with a workshop titled Coral Disease and Health Workshop: Developing Diagnostic Criteria co-convened by the Coral Disease and Health Consortium (CDHC), a working group organized under the auspices of the U.S. Coral Reef Task Force, and the International Registry for Coral Pathology (IRCP). The workshop was hosted by the U.S. Geological Survey, National Wildlife Health Center (NWHC) in Madison, Wisconsin and was focused on gross morphology and disease signs observed in the field. A resounding recommendation from the histopathologists participating in the workshop was the urgent need to develop diagnostic criteria that are suitable to move from gross observations to morphological diagnoses based on evaluation of microscopic anatomy. (PDF contains 92 pages

Biogeography and taxonomy of extinct and endangered monk seals illuminated by ancient DNA and skull morphology

Extinctions and declines of large marine vertebrates have major ecological impacts and are of critical concern in marine environments. The Caribbean monk seal, Monachus tropicalis, last definitively reported in 1952, was one of the few marine mammal species to become extinct in historical times. Despite its importance for understanding the evolutionary biogeography of southern phocids, the relationships of M. tropicalis to the two living species of critically endangered monk seals have not been resolved. In this study we present the first molecular data for M. tropicalis, derived from museum skins. Phylogenetic analysis of cytochrome b sequences indicates that M. tropicalis was more closely related to the Hawaiian rather than the Mediterranean monk seal. Divergence time estimation implicates the formation of the Panamanian Isthmus in the speciation of Caribbean and Hawaiian monk seals. Molecular, morphological and temporal divergence between the Mediterranean and "New World monk seals" (Hawaiian and Caribbean) is profound, equivalent to or greater than between sister genera of phocids. As a result, we classify the Caribbean and Hawaiian monk seals together in a newly erected genus, Neomonachus. The two genera of extant monk seals (Monachus and Neomonachus) represent old evolutionary lineages each represented by a single critically endangered species, both warranting continuing and concerted conservation attention and investment if they are to avoid the fate of their Caribbean relative.Dirk-Martin Scheel, Graham J. Slater, Sergios-Orestis Kolokotronis, Charles W. Potter, David S. Rotstein, Kyriakos Tsangaras, Alex D. Greenwood, Kristofer M. Helge