Dung’s abstract Argumentation Framework (AF) has emerged as a key formalism for argumentation in artificial intelligence. It has been extended in several directions, including the possibility to express supports, leading to the development of the Bipolar Argumentation Framework (BAF), and recursive attacks and supports, resulting in the Recursive BAF (Rec-BAF). Different interpretations of supports have been proposed, whereas for Rec-BAF (where the target of attacks and supports may also be attacks and supports) even different semantics for attacks have been defined. However, the semantics of these frameworks have either not been defined in the presence of support cycles or are often quite intricate in terms of the involved definitions. We encompass this limitation and present classical semantics for general BAF and Rec-BAF and show that the semantics for specific BAF and Rec-BAF frameworks can be defined by very simple and intuitive modifications of that defined for the case of AF. This is achieved by providing a modular definition of the sets of defeated and acceptable elements for each AF-based framework. We also characterize, in an elegant and uniform way, the semantics of general BAF and Rec-BAF in terms of logic programming and partial stable model semantics.

COVID-19 vaccine effectiveness (VE) studies are limited in low- and middle-income countries. A case-control study was conducted among COVID-19 and other pneumonia patients admitted to a hospital in the Philippines during the pre-Omicron and Omicron periods. To elucidate factors associated with in-hospital death, 1782 COVID-19 patients were assessed. To estimate absolute VE for various severe outcomes, 1059 patients were assessed (869 [82.1%] COVID-19 cases; 190 [17.9%] controls). Factors associated with in-hospital death included older age, tuberculosis (adjusted odds ratio [aOR] 2.45 [95% confidence interval {95% CI} 1.69–3.57]), HIV (aOR 3.30 [95% CI 2.03–5.37]), and current smokers (aOR 2.65 [95% CI 1.72–4.10]). Pre-Omicron, the primary series provided high protection within a median of 2 months (hospitalization: 85.4% [95% CI 35.9–96.7%]; oxygen requirement: 91.0% [95% CI 49.4–98.4%]; invasive mechanical ventilation (IMV): 97.0% [95% CI 65.7–99.7%]; death: 96.5% [95% CI 67.1–99.6%]). During Omicron, the primary series provided moderate-high protection within a median of 6–9 months (hospitalization: 70.2% [95% CI 27.0–87.8%]; oxygen requirement: 71.4% [95% CI 29.3–88.4%]; IMV: 72.7% [95% CI −11.6–93.3%]; death: 58.9% [95% CI −82.8–90.8%]). Primary series VE against severe COVID-19 outcomes was consistently high for both pre-Omicron and Omicron in a setting where approximately half of the vaccinees received inactivated vaccines.

Data exchange, the problem of transferring data from a source schema to a target schema, has been studied for several years. The semantics of answering positive queries over the target schema has been defined in early work, but little attention has been paid to more general queries. A few proposals of semantics for more general queries exist but they either do not properly extend the standard semantics under positive queries, giving rise to counterintuitive answers, or they make query answering undecidable even for the most important data exchange settings, for example, with weakly-acyclic dependencies.

The goal of this paper is to provide a new semantics for data exchange that is able to deal with general queries. At the same time, we want our semantics to coincide with the classical one when focusing on positive queries, and to not trade-off too much in terms of complexity of query answering. We show that query answering is undecidable in general under the new semantics, but it is $\text{co}\text{NP}\text{-complete}$ when the dependencies are weakly-acyclic. Moreover, in the latter case, we show that exact answers under our semantics can be computed by means of logic programs with choice, thus exploiting existing efficient systems. For more efficient computations, we also show that our semantics allows for the construction of a representative target instance, similar in spirit to a universal solution, that can be exploited for computing approximate answers in polynomial time.

The case for the superiority of Conviction Narrative Theory (CNT) over probabilistic approaches rests on selective employment of a double standard. The authors judge probabilistic approaches inadequate for failing to apply to “grand-world” decision problems, while they praise CNT for its treatment of “small-world” decision problems. When both approaches are held to the same standard, the comparative question is murkier.

OBJECTIVES/GOALS: Chronic low back pain (cLBP) is associated with gait impairments. Gait may serve as an important biomarker for improvement following therapy interventions; however, gait has not been sufficiently studied in relationship to pain and function in cLBP. METHODS/STUDY POPULATION: Adults with cLBP completed a two-minute-walk-test around a 37.5 m oval track while wearing an inertial measurement unit (IMU—Lifeware LLC, Pittsburgh, PA) over the L5 spinous process. Step time average, step time variability, step length, and symmetry (harmonic ratio) were calculated based on linear trunk accelerations, and gait speed was calculated based on distance walked. Participants completed the PEG tool (Pain, Enjoyment, General activity; scores closer to 10 indicate worse pain) to quantify pain intensity/interference and the PROMIS Physical Function SF-6b tool (mean t-scores=50 +/- 10; higher scores indicate better function) to quantify physical function. Pearson correlation coefficient (r) was used to determine strength of associations between gait and pain/physical function. RESULTS/ANTICIPATED RESULTS: Eleven adults (8 female, age 40 +/- 17, pain duration≥3 months) with cLPB participated in this study after completing an informed consent process approved by the University of Pittsburgh Institutional Review Board. Participants with a history of cancer, spinal cord compression, discitis, or activity restrictions prohibiting them from protocol completion were excluded. The mean PEG scores and PROMIS Physical Function t-scores were 2.8 +/- 1.8 and 47.8 +/- 8.2 respectively. There was a moderate-strong correlation between step time average and PEG (r=0.67, p=0.02), and a moderate-strong correlation between gait speed and PROMIS Physical Function (r=0.62, p=0.04). There were no other significant associations. DISCUSSION/SIGNIFICANCE: Gait speed and step time may be important movement biomarkers to consider when evaluating patients with cLBP. Generalizability of results are limited by the small study cohort and this cohort's relatively low pain burden and high level of physical function.

In this paper, we prove the existence of topologically non-trivial solutions of the two-dimensional Adkins–Nappi model of nuclear physics; to this end, we minimize the energy functional by using the classical Skyrme ansatz, as well as a non-radially symmetric generalization of it. In both cases, we show that the minimization procedure preserves the topological degree of the minimization sequence.