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

Long-term prognostic value of quantitative myocardial perfusion in patients with chest pain and normal coronary arteries

BACKGROUND: Patients with chest pain and no obstructive coronary artery disease have shown a high incidence of major adverse cardiovascular events (MACE). We evaluated the role of absolute myocardial perfusion quantification in predicting all-cause mortality and MACE during long-term follow-up in this group of patients. METHODS: We studied 79 patients who underwent Nitrogen-13 ammonia PET for quantification of global myocardial blood flow (MBF) and myocardial flow reserve (MFR) due to suspected impaired myocardial perfusion. Patients with coronary artery disease (i.e., > 30% stenosis in one or more coronary arteries) were excluded. We assessed all-cause mortality and MACE. MACE was defined as the composite incidence of death, myocardial infarction (MI), or hospitalization due to heart failure. RESULTS: Median follow-up was 8 (IQR: 3-14) years. Univariate Cox regression showed that only MFR (P = 0.01) was a predictor of all-cause mortality. Univariate Cox regression analysis showed that both MFR and Stress MBF were predictors of the composite endpoint of MACE (P < 0.001 and P = 0.01, respectively). CONCLUSION: Quantitative assessment of myocardial perfusion may predict all-cause mortality and MACE in patients with chest pain and normal coronary arteries in the long-term follow-up

Cardiovascular magnetic resonance native T-2 and T-2* quantitative values for cardiomyopathies and heart transplantations:a systematic review and meta-analysis

Background: The clinical application of cardiovascular magnetic resonance (CMR) T2 and T2* mapping is currently limited as ranges for healthy and cardiac diseases are poorly defined. In this meta-analysis we aimed to determine the weighted mean of T2 and T2* mapping values in patients with myocardial infarction (MI), heart transplantation, non-ischemic cardiomyopathies (NICM) and hypertension, and the standardized mean difference (SMD) of each population with healthy controls. Additionally, the variation of mapping outcomes between studies was investigated. Methods: The PRISMA guidelines were followed after literature searches on PubMed and Embase. Studies reporting CMR T2 or T2* values measured in patients were included. The SMD was calculated using a random effects model and a meta-regression analysis was performed for populations with sufficient published data. Results: One hundred fifty-four studies, including 13,804 patient and 4392 control measurements, were included. T2 values were higher in patients with MI, heart transplantation, sarcoidosis, systemic lupus erythematosus, amyloidosis, hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM) and myocarditis (SMD of 2.17, 1.05, 0.87, 1.39, 1.62, 1.95, 1.90 and 1.33, respectively, P < 0.01) compared with controls. T2 values in iron overload patients (SMD =-0.54, P = 0.30) and Anderson-Fabry disease patients (SMD = 0.52, P = 0.17) did both not differ from controls. T2* values were lower in patients with MI and iron overload (SMD of-1.99 and-2.39, respectively, P < 0.01) compared with controls. T2* values in HCM patients (SMD =-0.61, P = 0.22), DCM patients (SMD =-0.54, P = 0.06) and hypertension patients (SMD =-1.46, P = 0.10) did not differ from controls. Multiple CMR acquisition and patient demographic factors were assessed as significant covariates, thereby influencing the mapping outcomes and causing variation between studies. Conclusions: The clinical utility of T2 and T2* mapping to distinguish affected myocardium in patients with cardiomyopathies or heart transplantation from healthy myocardium seemed to be confirmed based on this meta-analysis. Nevertheless, variation of mapping values between studies complicates comparison with external values and therefore require local healthy reference values to clinically interpret quantitative values. Furthermore, disease differentiation seems limited, since changes in T2 and T2* values of most cardiomyopathies are similar

Validation of thoracic aortic dimensions on ECG-triggered SSFP as alternative to contrast-enhanced MRA

Objectives: Assessment of thoracic aortic dimensions with non-ECG-triggered contrast-enhanced magnetic resonance angiography (CE-MRA) is accompanied with motion artefacts and requires gadolinium. To avoid both motion artefacts and gadolinium administration, we evaluated the similarity and reproducibility of dimensions measured on ECG-triggered, balanced steady-state free precession (SSFP) MRA as alternative to CE-MRA. Methods: All patients, with varying medical conditions, referred for thoracic aortic examination between September 2016 and March 2018, who underwent non-ECG-triggered CE-MRA and SSFP-MRA (1.5 T) were retrospectively included (n = 30). Aortic dimensions were measured after double-oblique multiplanar reconstruction by two observers at nine landmarks predefined by literature guidelines. Image quality was scored at the sinus of Valsalva, mid-ascending aorta and mid-descending aorta by semi-automatically assessing the vessel sharpness. Results: Aortic dimensions showed high agreement between non-ECG-triggered CE-MRA and SSFP-MRA (r = 0.99, p < 0.05) without overestimation or underestimation of aortic dimensions in SSFP-MRA (mean difference, 0.1 mm; limits of agreement, − 1.9 mm and 1.9 mm). Intra- and inter-observer variabilities were significantly smaller with SSFP-MRA for the sinus of Valsalva and sinotubular junction. Image quality of the sinus of Valsalva was significantly better with SSFP-MRA, as fewer images were of impaired quality (3/30) than in CE-MRA (21/30). Reproducibility of dimensions was significantly better in images scored as good quality compared to impaired quality in both sequences. Conclusions: Thoracic aortic dimensions measured on SSFP-MRA and non-ECG-triggered CE-MRA were similar. As expected, SSFP-MRA showed better reproducibility close to the aortic root because of lesser motion artefacts, making it a feasible non-contrast imaging alternative. Key Points: • SSFP-MRA provides similar dimensions as non-ECG-triggered CE-MRA. • Intra- and inter-observer reproducibilities improve for the sinus of Valsalva and sinotubular junction with SSFP-MRA. • ECG-triggered SSFP-MRA shows better image quality for landmarks close to the aortic root in the absence of cardiac motion

Normative Autonomy and Normative Co-ordination: Declarative Power, Representation, and Mandate

In this paper we provide a formal analysis of the idea of normative co-ordination. We argue that this idea is based on the assumption that agents can achieve flexible co-ordination by conferring normative positions to other agents. These positions include duties, permissions, and powers. In particular, we explain the idea of declarative power, which consists in the capacity of the power-holder of creating normative positions, involving other agents, simply by "proclaiming" such positions. In addition, we account also for the concepts of representation, namely the representative's capacity of acting in the name of his principal, and of mandate, which is the mandatee's duty to act as the mandator has requested. Finally, we show how the framework can be applied to represent the contract-net protocol. Some brief remarks on future research and applications conclude this contribution

A Decidable Multi-agent Logic for Reasoning About Actions, Instruments, and Norms

We formally introduce a novel, yet ubiquitous, category of norms: norms of instrumentality. Norms of this category describe which actions are obligatory, or prohibited, as instruments for certain purposes. We propose the Logic of Agency and Norms (LAN) that enables reasoning about actions, instrumentality, and normative principles in a multi-agent setting. Leveraging LAN , we formalize norms of instrumentality and compare them to two prevalent norm categories: norms to be and norms to do. Last, we pose principles relating the three categories and evaluate their validity vis-à-vis notions of deliberative acting. On a technical note, the logic will be shown decidable via the finite model property

Image quality assessment of the right ventricle with three different delayed enhancement sequences in patients suspected of ARVC/D

Histopathologic findings in arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) are replacement of the normal myocardium with fatty and fibrous elements with preferential involvement of the right ventricle. The right ventricular fibrosis can be visualised by post-gadolinium delayed enhancement inversion recovery imaging (DE imaging). We compared the image quality of three different gradient echo MRI sequences for short axis DE imaging of the right ventricle (RV). We retrospectively analysed MRI scans performed between February 2005 and December 2008 in 97 patients (mean age: 41.2 years, 67% men) suspected of ARVC/D. For DE imaging either a 2D Phase Sensitive (PSIR), a 2D (2D) or a 3D (3D) inversion recovery sequence was used in respectively 38, 32 and 27 MRI-examinations. The RV, divided in 10 segments, was assessed for image quality by two radiologists in random sequence. A consensus reading was performed if results differed between the two readings. Image quality was good in 24% of all segments in the 3D group, 66% in the 2D group and 79% in the PSIR group. Poor image quality was observed in 51% (3D), 10% (2D), and 2% (PSIR) of all segments. Exams were considered suitable for clinical use in 7% of exams in the 3D group, 75% of exams in the 2D group and 90% of exams of the PSIR group. Breathing-artifacts occurred in 22% (3D), 59% (2D) and 53% (PSIR). Motion-artifacts occurred in 56% (3D), 28% (2D) and 29% (PSIR). Post-gadolinium imaging using the PSIR sequence results in better and more consistent image quality of the RV compared to the 2D and 3D sequences