Representation results for defeasible logic

The importance of transformations and normal forms in logic programming, and generally in computer science, is well documented. This paper investigates transformations and normal forms in the context of Defeasible Logic, a simple but efficient formalism for nonmonotonic reasoning based on rules and priorities. The transformations described in this paper have two main benefits: on one hand they can be used as a theoretical tool that leads to a deeper understanding of the formalism, and on the other hand they have been used in the development of an efficient implementation of defeasible logic.Comment: 30 pages, 1 figur

Neural processing of imminent collision in humans

Detecting a looming object and its imminent collision is imperative to survival. For most humans, it is a fundamental aspect of daily activities such as driving, road crossing and participating in sport, yet little is known about how the brain both detects and responds to such stimuli. Here we use functional magnetic resonance imaging to assess neural response to looming stimuli in comparison with receding stimuli and motion-controlled static stimuli. We demonstrate for the first time that, in the human, the superior colliculus and the pulvinar nucleus of the thalamus respond to looming in addition to cortical regions associated with motor preparation. We also implicate the anterior insula in making timing computations for collision events

An fMRI study of parietal cortex involvement in the visual guidance of locomotion

Locomoting through the environment typically involves anticipating impending changes in heading trajectory in addition to maintaining the current direction of travel. We explored the neural systems involved in the “far road” and “near road” mechanisms proposed by Land and Horwood (1995) using simulated forward or backward travel where participants were required to gauge their current direction of travel (rather than directly control it). During forward egomotion, the distant road edges provided future path information, which participants used to improve their heading judgments. During backward egomotion, the road edges did not enhance performance because they no longer provided prospective information. This behavioral dissociation was reflected at the neural level, where only simulated forward travel increased activation in a region of the superior parietal lobe and the medial intraparietal sulcus. Providing only near road information during a forward heading judgment task resulted in activation in the motion complex. We propose a complementary role for the posterior parietal cortex and motion complex in detecting future path information and maintaining current lane positioning, respectively. (PsycINFO Database Record (c) 2010 APA, all rights reserved

Trades in complex Hadamard matrices

A trade in a complex Hadamard matrix is a set of entries which can be changed to obtain a different complex Hadamard matrix. We show that in a real Hadamard matrix of order $n$ all trades contain at least $n$ entries. We call a trade rectangular if it consists of a submatrix that can be multiplied by some scalar $c \neq 1$ to obtain another complex Hadamard matrix. We give a characterisation of rectangular trades in complex Hadamard matrices of order $n$ and show that they all contain at least $n$ entries. We conjecture that all trades in complex Hadamard matrices contain at least $n$ entries.Comment: 9 pages, no figure

Regional innovation in arts provision spawned by COVID-19: ‘It became a lifeline for a lot of people who are stuck at home’

Although the impact of the global COVID-19 pandemic on the arts and cultural sector due to the closure of galleries, museums, arts venues, and other cultural assets represents a significant health risk, new opportunities for arts and cultural engagement have arisen. Interviews with 24 representatives including service providers and creative practitioners from 15 arts and cultural organizations within the Liverpool City Region were conducted. The aim was to examine the impact of COVID-19 on arts and cultural provision and on organizations and people providing these services, as well as to understand the perceptions of service providers and practitioners of the effects on those whom arts and cultural organizations serve, including those who would usually access arts through formal healthcare routes (e.g., through collaboration with health partners). Interview data were analyzed using framework analysis. Four overarching themes were identified: Response: Closures, adaptations, and new directions; Challenges of online provision; Value of online provision; and the future of the arts. The arts and cultural sector has innovated rapidly, notably with accelerated digitalisation. Alternative provision has been “a lifeline” for vulnerable groups, such as those with mental health difficulties. Arts organizations have been most effective in reaching vulnerable, isolated and disadvantaged populations when they have worked in close collaboration with health and social care providers. The implementation of hybrid provision is an important move forward for the sector in light of our findings that alternative modes of provision are advantageous additions to service as usual. Given the increasing concerns about the mental health sequelae of the pandemic in the UK, arts and cultural engagement could play a pivotal role in the future recovery period

A versatile high resolution objective for imaging quantum gases

We present a high resolution objective lens made entirely from catalog singlets that has a numerical aperture of 0.36. It corrects for aberrations introduced by a glass window and has a long working distance of 35mm, making it suitable for imaging objects within a vacuum system. This offers simple high resolution imaging for many in the quantum gas community. The objective achieves a resolution of 1.3{\mu}m at the design wavelength of 780nm, and a diffraction-limited field of view of 360{\mu}m when imaging through a 5mm window. Images of a resolution target and a pinhole show quantitative agreement with the simulated lens performance. The objective is suitable for diffraction-limited imaging on the D2 line of all the alkalis by changing only the aperture diameter, retaining numerical apertures above 0.32. The design corrects for window thicknesses of up to 15mm if the singlet spacings are modified

Billy Elliot The Musical: visual representations of working-class masculinity and the all-singing, all-dancing bo[d]y

According to Cynthia Weber, ‘[d]ance is commonly thought of as liberating, transformative, empowering, transgressive, and even as dangerous’. Yet ballet as a masculine activity still remains a suspect phenomenon. This paper will challenge this claim in relation to Billy Elliot the Musical and its critical reception. The transformation of the visual representation of the human body on stage (from an ephemeral existence to a timeless work of art) will be discussed and analysed vis-a-vis the text and sub-texts of Stephen Daldry’s direction and Peter Darling’s choreography. The dynamics of working-class masculinity will be contextualised within the framework of the family, the older female, the community, the self and the act of dancing itself

Back to live: Returning to in-person engagement with arts and culture in the Liverpool City Region

On July 19th 2021, the UK government lifted the COVID-19 restrictions that had been in place since March 2020, including wearing masks, social distancing, and all other legal requirements. The return to in-person events has been slow and gradual, showing that audiences are still cautious when (and if) they resume engaging in arts and culture. Patterns of audience behavior have also changed, shifting toward local attendance, greater digital and hybrid engagement, and openness to event format changes. As the arts and cultural industry recovers from the pandemic, it is important to adopt an audience-oriented approach and look at the changing patterns of engaging in arts and culture. This study aims to better understand the impact of the pandemic on the patterns of cultural and arts engagement. Eight qualitative interviews were conducted to explore the changes in arts and cultural engagement since the restrictions were lifted, focusing particularly on the audience’s experiences of returning to in-person arts and cultural events in the Liverpool City Region (LCR). Using framework analysis, three themes were identified from the data: The new normal: reframing pre-pandemic and pandemic experiences of arts and culture, Re-adjusting to in-person provision, and Moving forward: online and blended provision. The findings show that the pandemic altered the ways that people engage in arts and culture. The “new normal,” a blend of pandemic and pre-pandemic experiences, illustrates how the pandemic has highlighted and reconfigured the importance of arts and culture, in terms of personal and cultural identity. Resuming in-person engagement after a long break, participants noted that they were able to feel more like themselves again. Arts and culture were perceived to be beneficial in rebuilding personal resilience and confidence. Engaging in arts and culture, following the isolating experience of the pandemic, has also helped participants feel reconnected to others through their shared experiences. Finally, the findings suggest that online provision remains vital for many, ensuring wider inclusivity, particularly for vulnerable audiences. At the same time, it is important to acknowledge the barriers to online inclusion and the possibility of this resulting in a growing digital divide