Charged Particles in a 2+1 Curved Background

The coupling to a 2+1 background geometry of a quantized charged test particle in a strong magnetic field is analyzed. Canonical operators adapting to the fast and slow freedoms produce a natural expansion in the inverse square root of the magnetic field strength. The fast freedom is solved to the second order. At any given time, space is parameterized by a couple of conjugate operators and effectively behaves as the `phase space' of the slow freedom. The slow Hamiltonian depends on the magnetic field norm, its covariant derivatives, the scalar curvature and presents a peculiar coupling with the spin-connection.Comment: 22 page

Determinants of impact : towards a better understanding of encounters with the arts

The article argues that current methods for assessing the impact of the arts are largely based on a fragmented and incomplete understanding of the cognitive, psychological and socio-cultural dynamics that govern the aesthetic experience. It postulates that a better grasp of the interaction between the individual and the work of art is the necessary foundation for a genuine understanding of how the arts can affect people. Through a critique of philosophical and empirical attempts to capture the main features of the aesthetic encounter, the article draws attention to the gaps in our current understanding of the responses to art. It proposes a classification and exploration of the factors—social, cultural and psychological—that contribute to shaping the aesthetic experience, thus determining the possibility of impact. The ‘determinants of impact’ identified are distinguished into three groups: those that are inherent to the individual who interacts with the artwork; those that are inherent to the artwork; and ‘environmental factors’, which are extrinsic to both the individual and the artwork. The article concludes that any meaningful attempt to assess the impact of the arts would need to take these ‘determinants of impact’ into account, in order to capture the multidimensional and subjective nature of the aesthetic experience

ECSA's Characteristics of Citizen Science: Explanation Notes

This explanation document provides an interpretation of and explanation for the characteristics document, which was kept short to make it useful to different stakeholders. In this document, the characteristics document is represented, with the original text in blue and an explanation in black

Get a Grip:Evaluating Grip Gestures for VR Input Using a Lightweight Pen

The use of Virtual Reality (VR) in applications such as data analysis, artistic creation, and clinical settings requires high precision input. However, the current design of handheld controllers, where wrist rotation is the primary input approach, does not exploit the human fingers' capability for dexterous movements for high precision pointing and selection. To address this issue, we investigated the characteristics and potential of using a pen as a VR input device. We conducted two studies. The first examined which pen grip allowed the largest range of motion---we found a tripod grip at the rear end of the shaft met this criterion. The second study investigated target selection via 'poking' and ray-casting, where we found the pen grip outperformed the traditional wrist-based input in both cases. Finally, we demonstrate potential applications enabled by VR pen input and grip postures

Imagining the Lives of Others: Empathy in Public Relations

This paper asks how we might theorise empathy in public relations (PR) in the light of a widespread ‘turn’ towards emotion in the academy, as well as in popular discourse. Two distinct notions of empathy are explored: ‘true’empathy as discussed in intercultural communication, is driven by a human concern for the other in order to understand experiences, feelings and situations that may be different from our own; whereas ‘instrumental’ empathy, reflecting a self orientation, is said to characterise much neoliberal market discourse in which corporations are urged to understand their customers better. Thus, while empathy may seem highly desirable as a means to enter into dialogue with an organisation’s publics, particularly during times of social upheaval and crisis, it is important to pay attention to empathy in public relations discourses including whose goals are served by empathetic engagement; and the type(s) of empathy called upon within a PR context. A literature review identified a socio-cultural definition of empathy as ‘imaginary effort’. A review of the public relations literature, however, found that while empathy is considered an important principle and personal attribute, notions of empathy, with a few exceptions, are under-explored. Nonfunctionalist, socio-cultural research which examines the meanings that practitioners associate with empathy is distinctly lacking; therefore in order to gain further insight into empathy, two sources of data were explored. The analysis of a popular online practitioner blog showed that other-centred empathic skill is discursively framed as instrumental in achieving clients’ business objectives. The analysis of three empathy statements drawn from 12 in-depth interviews with practitioners revealed complex empathic discourse in practitioner-client relationships. While the findings are limited to illustrative analyses only, this paper challenges researchers to develop conceptualisations and perspectives of empathy as imaginary effort in public relations

The use of composite pulses for improving DEER signal at 94 GHz

C.L.M. acknowledges funding from EPSRC as part of the iMRCDT. The W-band instrument was developed under the U.K. Research Councils Basic Technology Program (grant EP/F039034/1). S.V.D. acknowledges the Research Foundation Flanders (FWO) for financial support (grant G.0687.13). J.E.L. thanks the Royal Society for a University Research Fellowship. Sylvia Dewilde (Biomedical Sciences, University of Antwerp) is thanked for the purification of the Cys46Ser/ Cys55Ser mutant of human neuroglobin (NGB) used in this work. Adelheid Godt’s group is thanked for the synthesis of MSA236. We also thank the Wellcome Trust (grant 099149/Z/12/Z). The research data (and/or materials) supporting this publication can be accessed at http://dx.doi.org/10.17630/b65d05e6-6efa-48b9-a741-5a6322159a4a.The sensitivity of pulsed electron paramagnetic resonance (EPR) measurements on broad-line paramagnetic centers is often limited by the available excitation bandwidth. One way to increase excitation bandwidth is through the use of chirp or composite pulses. However, performance can be limited by cavity or detection bandwidth, which in commercial systems is typically 100-200 MHz. Here we demonstrate in a 94 GHz spectrometer, with > 800 MHz system bandwidth, an increase in signal and modulation depth in a 4-pulse DEER experiment through use of composite rather than rectangular π pulses. We show that this leads to an increase in sensitivity by a factor of 3, in line with theoretical predictions, although gains are more limited in nitroxide-nitroxide DEER measurements.PostprintPeer reviewe

Convection and Retro-Convection Enhanced Delivery: Some Theoretical Considerations Related to Drug Targeting

Delivery of drugs and macromolecules into the brain is a challenging problem, due in part to the blood–brain barrier. In this article, we focus on the possibilities and limitations of two infusion techniques devised to bypass the blood–brain barrier: convection enhanced delivery (CED) and retro-convection enhanced delivery (R-CED). CED infuses fluid directly into the interstitial space of brain or tumor, whereas R-CED removes fluid from the interstitial space, which results in the transfer of drugs from the vascular compartment into the brain or tumor. Both techniques have shown promising results for the delivery of drugs into large volumes of tissue. Theoretical approaches of varying complexity have been developed to better understand and predict brain interstitial pressures and drug distribution for these techniques. These theoretical models of flow and diffusion can only be solved explicitly in simple geometries, and spherical symmetry is usually assumed for CED, while axial symmetry has been assumed for R-CED. This perspective summarizes features of these models and provides physical arguments and numerical simulations to support the notion that spherical symmetry is a reasonable approximation for modeling CED and R-CED. We also explore the potential of multi-catheter arrays for delivering and compartmentalizing drugs using CED and R-CED

Contours of Citizen Science: A Vignette Study

Citizen science has expanded rapidly over the past decades. Yet, defining citizen science and its boundaries remained a challenge, and this is reflected in the literature - for example in the proliferation of typologies and definitions. There is a need for identifying areas of agreement and disagreement within the citizen science practitioners community on what should be considered as citizen science activity. This paper describes the development and results of a survey that examined this issue, through the use of vignettes - short case descriptions that describe an activity, while asking the respondents to rate the activity on a scale from ‘not citizen science’ (0%) to ‘citizen science’ (100%). The survey included 50 vignettes, of which 5 were developed as clear cases of not-citizen science activities, 5 as widely accepted citizen science activities, and the others addressing 10 factors and 61 sub-factors that can lead to controversy about an activity. The survey has attracted 333 respondents, who provided over 5,100 ratings. The analysis demonstrates the plurality of understanding of what citizen science is and calls for an open understanding of what activities are included in the field

Role of chaos for the validity of statistical mechanics laws: diffusion and conduction

Several years after the pioneering work by Fermi Pasta and Ulam, fundamental questions about the link between dynamical and statistical properties remain still open in modern statistical mechanics. Particularly controversial is the role of deterministic chaos for the validity and consistency of statistical approaches. This contribution reexamines such a debated issue taking inspiration from the problem of diffusion and heat conduction in deterministic systems. Is microscopic chaos a necessary ingredient to observe such macroscopic phenomena?Comment: Latex, 27 pages, 10 eps-figures. Proceedings of the Conference "FPU 50 years since" Rome 7-8 May 200

Discourse, justification and critique: towards a legitimate digital copyright regime?

Digitization and the internet have posed an acute economic challenge to rights holders in the cultural industries. Faced with a threat to their form of capital accumulation from copyright infringement, rights holders have used discourse strategically in order to try and legitimate and strengthen their position in the digital copyright debate with governments and media users. In so doing, they have appealed to general justificatory principles – about what is good, right, and just – that provide some scope for opposition and critique, as other groups contest their interpretation of these principles and the evidence used to support them. In this article, we address the relative lack of academic attention paid to the role of discourse in copyright debates by analysing user-directed marketing campaigns and submissions to UK government policy consultations. We show how legitimacy claims are justified and critiqued, and conclude that amid these debates rests some hope of achieving a more legitimate policy resolution to the copyright wars – or at least the possibility of beginning a more constructive dialogue