1,042 research outputs found
Analysis of Dialogical Argumentation via Finite State Machines
Dialogical argumentation is an important cognitive activity by which agents
exchange arguments and counterarguments as part of some process such as
discussion, debate, persuasion and negotiation. Whilst numerous formal systems
have been proposed, there is a lack of frameworks for implementing and
evaluating these proposals. First-order executable logic has been proposed as a
general framework for specifying and analysing dialogical argumentation. In
this paper, we investigate how we can implement systems for dialogical
argumentation using propositional executable logic. Our approach is to present
and evaluate an algorithm that generates a finite state machine that reflects a
propositional executable logic specification for a dialogical argumentation
together with an initial state. We also consider how the finite state machines
can be analysed, with the minimax strategy being used as an illustration of the
kinds of empirical analysis that can be undertaken.Comment: 10 page
Molecular characterization of Trichomonas gallinae isolates recovered from the Canadian Maritime provinces’ wild avifauna reveals the presence of the genotype responsible for the European finch trichomonosis epidemic and additional strains
Finch trichomonosis, caused by Trichomonas gallinae, emerged in the Canadian Maritime provinces in 2007 and has since caused ongoing mortality in regional purple finch (Carpodacus purpureus) and American goldfinch (Carduelis tristis) populations. Trichomonas gallinae was isolated from (1) finches and rock pigeons (Columbia livia) submitted for post-mortem or live-captured at bird feeding sites experiencing trichomonosis mortality; (2) bird seed at these same sites; and (3) rock pigeons live-captured at known roosts or humanely killed. Isolates were characterized using internal transcribed spacer (ITS) region and iron hydrogenase (Fe-hyd) gene sequences. Two distinct ITS types were found. Type A was identical to the UK finch epidemic strain and was isolated from finches and a rock pigeon with trichomonosis; apparently healthy rock pigeons and finches; and bird seed at an outbreak site. Type B was obtained from apparently healthy rock pigeons. Fe-hyd sequencing revealed six distinct subtypes. The predominant subtype in both finches and the rock pigeon with trichomonosis was identical to the UK finch epidemic strain A1. Single nucleotide polymorphisms in Fe-hyd sequences suggest there is fine-scale variation amongst isolates and that finch trichomonosis emergence in this region may not have been caused by a single spill-over event
What Are The Next Three Terms In This Sequence?
Continuing a sequence when the first three terms are provided is a problem that students encounter at many levels of instruction. Consider the following: 3, 6, 9, __, __, __. When asked to fill in the blanks, many students (and more than a few teachers) mistakenly believe that there is only one correct answer. In the following article, the authors explore alternative solutions to such tasks, confirming that—in fact—such questions have many correct answers. Using a mix of by-hand and technology-based approaches, the authors explore three different types of sequences and show how to determine the explicit formula for each based on the term that is chosen next
Dating the Cryptococcus gattii Dispersal to the North American Pacific Northwest.
The emergence of Cryptococcus gattii, previously regarded as a predominantly tropical pathogen, in the temperate climate of the North American Pacific Northwest (PNW) in 1999 prompted several questions. The most prevalent among these was the timing of the introduction of this pathogen to this novel environment. Here, we infer tip-dated timing estimates for the three clonal C. gattii populations observed in the PNW, VGIIa, VGIIb, and VGIIc, based on whole-genome sequencing of 134 C. gattii isolates and using Bayesian evolutionary analysis by sampling trees (BEAST). We estimated the nucleotide substitution rate for each lineage (1.59 × 10-8, 1.59 × 10-8, and 2.70 × 10-8, respectively) to be an order of magnitude higher than common neutral fungal mutation rates (2.0 × 10-9), indicating a microevolutionary rate (e.g., successive clonal generations in a laboratory) in comparison to a species' slower, macroevolutionary rate (e.g., when using fossil records). The clonal nature of the PNW C. gattii emergence over a narrow number of years would therefore possibly explain our higher mutation rates. Our results suggest that the mean time to most recent common ancestor for all three sublineages occurred within the last 60 to 100 years. While the cause of C. gattii dispersal to the PNW is still unclear, our research estimates that the arrival is neither ancient nor very recent (i.e., <25 years ago), making a strong case for an anthropogenic introduction. IMPORTANCE The recent emergence of the pathogenic fungus Cryptococcus gattii in the Pacific Northwest (PNW) resulted in numerous investigations into the epidemiological and enzootic impacts, as well as multiple genomic explorations of the three primary molecular subtypes of the fungus that were discovered. These studies lead to the general conclusion that the subtypes identified likely emerged out of Brazil. Here, we conducted genomic dating analyses to determine the ages of the various lineages seen in the PNW and propose hypothetical causes for the dispersal events. Bayesian evolutionary analysis strongly suggests that these independent fungal populations in the PNW are all 60 to 100 years old, providing a timing that is subsequent to the opening of the Panama Canal, which allowed for more direct shipping between Brazil and the western North American coastline, a possible driving event for these fungal translocation events
On the emergent Semantic Web and overlooked issues
The emergent Semantic Web, despite being in its infancy, has already received a lotof attention from academia and industry. This resulted in an abundance of prototype systems and discussion most of which are centred around the underlying infrastructure. However, when we critically review the work done to date we realise that there is little discussion with respect to the vision of the Semantic Web. In particular, there is an observed dearth of discussion on how to deliver knowledge sharing in an environment such as the Semantic Web in effective and efficient manners. There are a lot of overlooked issues, associated with agents and trust to hidden assumptions made with respect to knowledge representation and robust reasoning in a distributed environment. These issues could potentially hinder further development if not considered at the early stages of designing Semantic Web systems. In this perspectives paper, we aim to help engineers and practitioners of the Semantic Web by raising awareness of these issues
Liver Parasites and Body Condition in Relation to Environmental Contaminants in Caribou (Rangifer tarandus) from Labrador, Canada
Over the last several decades, elders and hunters of the Innu Nation in Labrador, Canada, have expressed concerns over perceived declines in environmental health and the integrity of country food, including caribou. The primary objective of this study was to determine links between specific health parameters and contaminants found in caribou from the George River herd. Twenty-seven caribou killed by local Innu hunters between February and December 2001 were evaluated for gross and microscopic pathology, body condition, liver parasitology, and contaminant levels in kidney and fat. Overall, the sampled caribou appeared to be in adequate body condition for the time of year, and no clinically significant lesions were found. Concentrations of selenium, metals (Hg, Cd, and Pb), 20 organochlorine pesticides (HCB, a-HCH, g-HCH, aldrin, dieldrin, methoxychlor, mirex, a- and b-endosulfan, heptachlor, heptachlor epoxide, g-CHL, cis-CHL, trans-nonachlor, and o,p'- and p,p'-DDD, DDE, DDT), and 24 PCB congeners were within the ranges reported for caribou in Canada. In general, contaminant levels were relatively low, with the exception of cadmium in kidneys (geometric mean: 6.5 μg/g wet weight; range: 1.5–44.0 μg/g). Two types of liver parasites were found: the liver fluke Fascioloides magna (prevalence: 78%; geometric mean abundance: 4.2 flukes/caribou) and a tapeworm larva consistent with Taenia hydatigena (prevalence: 50%; geometric mean abundance: 0.6 larvae/caribou). Using multiple variable regression analysis, we found renal concentrations of cadmium to be positively associated, and selenium to be negatively associated, with F. magna abundance.Ces dernières décennies, les aînés et les chasseurs de la nation montagnaise du Labrador, au Canada, ont exprimé des inquiétudes au sujet du déclin de la santé de l’environnement et de l’intégrité de la nourriture provenant de la campagne, telle que le caribou. L’objectif principal de cette étude consistait à déterminer les liens qui existent entre certains paramètres de santé précis et les contaminants se trouvant dans le caribou du troupeau de la rivière George. Vingt-sept caribous ayant été tués par les chasseurs montagnais de la région entre les mois de février et de décembre 2001 ont subi des examens pathologiques macroscopiques et microscopiques, en plus d’avoir été évalués pour en déterminer l’état du corps, la parasitologie du foie et les taux de contaminants dans le foie et le gras. Dans l’ensemble, l’état des corps de caribous échantillonnés semblait adéquat pour cette période de l’année et aucune lésion clinique importante n’a été signalée. Les concentrations de sélénium, de métaux (Hg, Cd et Pb), de 20 pesticides organochlorés (HCB, a-HCH, g-HCH, aldrine, dieldrine, méthoxychlore, mirex, a- et b-endosulfane, heptachlore, heptachlorépoxyde, g-CHL, cis-CHL, trans-nonachlore ainsi que o,p'- et p,p'-DDD, DDE, DDT) et de 24 congénères de PCB s’établissaient dans les étendues signalées pour le caribou au Canada. En général, les niveaux de contaminants étaient relativement faibles, à l’exception du cadmium se trouvant dans les reins (moyenne géometrique : 6,5 μg/g poids humide; étendue : 1,5–44,0 mg/g). Deux types de parasites du foie ont été trouvés : la douve Fascioloides magna (prévalence : 78 %; abondance moyenne géométrique : 4,2 douves/caribou) et un cestode du genre Taenia hydatigena (prévalence : 50 %; abondance moyenne géométrique : 0,6 larves/caribou). Nous avons également réalisé une analyse de régression à variables multiples qui nous a permis de constater que les concentrations de cadmium sont positivement associées et celles de sélénium sont négativement associées à l’abondance de F. magna
Work‐Related Outcomes After a Myocardial Infarction
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90385/1/phco.24.16.1515.50946.pd
Health‐Related Quality of Life in Patients 7 Months After a Myocardial Infarction: Factors Affecting the Short Form‐12
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90293/1/phco.22.17.1616.34121.pd
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