The sigma orientation for analytic circle-equivariant elliptic cohomology

We construct a canonical Thom isomorphism in Grojnowski's equivariant elliptic cohomology, for virtual T-oriented T-equivariant spin bundles with vanishing Borel-equivariant second Chern class, which is natural under pull-back of vector bundles and exponential under Whitney sum. It extends in the complex-analytic case the non-equivariant sigma orientation of Hopkins, Strickland, and the author. The construction relates the sigma orientation to the representation theory of loop groups and Looijenga's weighted projective space, and sheds light even on the non-equivariant case. Rigidity theorems of Witten-Bott-Taubes including generalizations by Kefeng Liu follow.Comment: Published in Geometry and Topology at http://www.maths.warwick.ac.uk/gt/GTVol7/paper3.abs.htm

Duration Judgement Deficits and Schizophrenic Liability: What Drives Them and Can They Be Manipulated

Duration judgements are a critical part of human life, and interest in this criticality is as ancient as the interest in the concept of time itself (e.g., Grondin, 2008). Judging the duration of an event or of passing time is also highly malleable, subject to both individual differences and environmental factors, e.g., heat or music. Retardation of duration judgements (e.g., judging the length of durations) are a common feature of schizophrenia (Elvevåg et al., 2003; Carroll et al., 2008; Carroll et al., 2009; Reed & Randell, 2014) however, there are patent difficulties in establishing the fundamental cause of timing deficits, in schizophrenia; which remains poorly understood. For example, it is well known that pharmaceutical interventions (e.g., haloperidol) can modify duration judgements (Rammsayer, 1990) in both normal adults and schizophrenic patients; however, external stimuli, such as an auditory Click Train (e.g., a series of clicks presented before stimuli), can also be used to modify duration judgments (albeit at a smaller effect-size than pharmaceutical interventions). Whether a Click Train has a similar effect as pharmacological interventions in schizophrenia has never been investigated and thus, there remains a paucity of research in this respect. To counter the potential effects of medication on duration judgements, schizotypy can be used as a useful construct for schizophrenia liability to investigate timing deficits in schizophrenia; as well as Click Train effectiveness in manipulating timing durations. Five experiments were conducted to examine what, fundamentally, contributes to timing deficits in schizotypy and to assess whether the Click Train can manipulate duration judgements in schizotypy. The first two experiments used the popular temporal bisection tasks in both visual and auditory modalities: as well as using a Click train The second set of experiments utilised the temporal generalisation tasks, using both visual and auditory modalities; as well as the Click Train. The final experiment used the classic estimation task, in which subjects had to estimate how long a video lasted. The first set of experiments are indicative of High Schizotypy subjects showing better precision for auditory durations, and that the Click Train manipulated judgement durations in subjects, irrespective of schizotypy level. The second set of experiments suggested memory distortions are present in Schizotypy and could be driving the timing deficits reported. The final experimental also implicates better precision in identifying durations in High Schizotypy. The Click Train manipulated duration judgements, irrespective of schizotypy level. Overall, the current thesis provides evidence that (1) timing deficits in schizotypy (and potentially, schizophrenia) are the result of better precision in identifying durations (e.g., less variability) and (2)., that the Click Train can be used as an effective tool in manipulating duration judgements in schizotypy and potentially limiting some of the effects of timing deficits in schizophrenia

Mangled Mantra: grotesque sound in the visual arts

This research paper examines how sound, namely the sound of the voice, functions as grotesque within the visual arts. The paper explores a number of ideas that frame the grotesque as a distorting, liminal force that works upon threshold areas to merge and combine unlikely forms. My research considers how vocal sounds might be viewed in relation to such a framework, by looking at my own and others work that use abstracted, non-linguistic vocalisations that have been altered through audio processing to produce a grotesque mode of voice. The project explores how this grotesque vocal sound can be incorporated into musical composition, and how these compositions can then be used as the basis to inform a range of visual work such as painting, drawing, objects, and video. In doing this, the research uses the metaphor of ventriloquism to examine how the grotesque voice might be seen to ‘speak’ through various visual art works

A Simple Non-equilibrium Feedback Model for Galaxy-Scale Star Formation: Delayed Feedback and SFR Scatter

We explore a class of simple non-equilibrium star formation models within the framework of a feedback-regulated model of the ISM, applicable to kiloparsec-scale resolved star formation relations (e.g. Kennicutt-Schmidt). Combining a Toomre-Q-dependent local star formation efficiency per free-fall time with a model for delayed feedback, we are able to match the normalization and scatter of resolved star formation scaling relations. In particular, this simple model suggests that large ($\sim$dex) variations in star formation rates (SFRs) on kiloparsec scales may be due to the fact that supernova feedback is not instantaneous following star formation. The scatter in SFRs at constant gas surface density in a galaxy then depends on the properties of feedback and when we observe its star-forming regions at various points throughout their collapse/star formation "cycles". This has the following important observational consequences: (1) the scatter and normalization of the Kennicutt-Schmidt relation are relatively insensitive to the local (small-scale) star formation efficiency, (2) but gas depletion times and velocity dispersions are; (3) the scatter in and normalization of the Kennicutt-Schmidt relation is a sensitive probe of the feedback timescale and strength; (4) even in a model where $\tilde Q_{\rm gas}$ deterministically dictates star formation locally, time evolution, variation in local conditions (e.g., gas fractions and dynamical times), and variations between galaxies can destroy much of the observable correlation between SFR and $\tilde Q_{\rm gas}$ in resolved galaxy surveys. Additionally, this model exhibits large scatter in SFRs at low gas surface densities, in agreement with observations of flat outer HI disk velocity dispersion profiles.Comment: 15 pages, 6 figures, accepted by MNRAS (04/25/2019

Polyurethane foam infill for fiber reinforced polymer (FRP) bridge deck panels: an evaluation of core alternatives using small scale experimental testing

Fiber reinforced polymer (FRP) decking is a concept that has been explored in recent decades as one solution to the performance issues of conventional concrete bridge decking. Many sandwich panel designs made of glass reinforced polyester or vinyl ester resin have been well developed, and manufactured using filament winding, hand lay-up, and extrusion methods. The major benefits of these panels was their light weight, corrosion resistance, fatigue performance, and potential for rapid field assembly. However, high initial costs coupled with small state budgets have kept them from main stream adoption. A viable alternative, is a foam/reinforced foam core sandwich panel made of polyurethane materials and glass fibers that is manufactured using the vacuum assisted resin transfer molding (VARTM) process. These type of panels could potentially decrease initial expenses, manufacturing difficulties, and possibly reduce weight further while retaining the benefits provided by previously explored FRP panels. The primary objective of this thesis is to evaluate three potential core alternatives. Type 1 consisted of a rigid polyurethane core, Type 2 consisted of a flexible polyurethane foam core reinforced by a grid work of resin infused glass fibers, and the Type 3 core consisted of trapezoidal blocks of flexible polyurethane foam reinforced with resin infused glass fiber shear layers. Four types of small scale experimental testing were conducted in this research; flatwise compression and tension testing, three point flexural testing, and four point flexural testing. The results showed that both the Type 1 and 2 cores were very weak and flexible making their implementation in bridge deck panels less practical. The Type 3 core was the stiffest and strongest core configuration making in the most practical for implementation in bridge deck panels --Abstract, page iii

Compliant rolling-contact architected materials for shape reconfigurability.

Architected materials can achieve impressive shape-changing capabilities according to how their microarchitecture is engineered. Here we introduce an approach for dramatically advancing such capabilities by utilizing wrapped flexure straps to guide the rolling motions of tightly packed micro-cams that constitute the material's microarchitecture. This approach enables high shape-morphing versatility and extreme ranges of deformation without accruing appreciable increases in strain energy or internal stress. Two-dimensional and three-dimensional macroscale prototypes are demonstrated, and the analytical theory necessary to design the proposed materials is provided and packaged as a software tool. An approach that combines two-photon stereolithography and scanning holographic optical tweezers is demonstrated to enable the fabrication of the proposed materials at their intended microscale

Children’s experience and attitudes towards the police, personal safety and public spaces: findings from the 2009/10 British Crime Survey interviews with children aged 10 to 15, supplementary volume 3 to Crime in England and Wales 2009/10

The British Crime Survey (BCS) is a face-to-face victimisation survey of around 46,000 adults resident in households in England and Wales. The survey has been carried out since 19821, asking adults aged 16 or over about their experiences of crime in the 12 months prior to interview as well as their attitudes towards different crime-related issues such as the police, criminal justice system, and perceptions of crime and anti-social behaviour. One of the key recommendations of crime statistics reviews carried out in 2006 was that the BCS should be extended to include populations currently not covered by the survey, for example, people aged under 16 (Smith, 2006; Statistics Commission, 2006). An announcement was made in May 2008 that the BCS would be extended to include children aged 10 to 15 following independent expert advice (Pickering et al., 2008). After a period of testing, development and consultation, data collection began in January 2009. A methodological report detailing all aspects of this process was published on 21 October 2010 (see Fitzpatrick et al., 2010)