A limiting velocity for quarkonium propagation in a strongly coupled plasma via AdS/CFT

We study the dispersion relations of mesons in a particular hot strongly coupled supersymmetric gauge theory plasma. We find that at large momentum k the dispersion relations become omega = v_0 k + a + b/k + ..., where the limiting velocity v_0 is the same for mesons with any quantum numbers and depends only on the ratio of the temperature to the quark mass T/m_q. We compute a and b in terms of the meson quantum numbers and T/m_q. The limiting meson velocity v_0 becomes much smaller than the speed of light at temperatures below but close to T_diss, the temperature above which no meson bound states at rest in the plasma are found. From our result for v_0, we find that the temperature above which no meson bound states with velocity v exist is T_diss(v) \simeq (1-v^2)^(1/4) T_diss, up to few percent corrections.We thus confirm by direct calculation of meson dispersion relations a result inferred indirectly in previous work via analysis of the screening length between a static quark and antiquark in a moving plasma. Although we do not do our calculations in QCD, we argue that the qualitative features of the dispersion relation we compute, including in particular the relation between dissociation temperature and meson velocity, may apply to bottomonium and charmonium mesons propagating in the strongly coupled plasma of QCD. We discuss how our results can contribute to understanding quarkonium physics in heavy ion collisions.Comment: 57 pages, 12 figures; references adde

Energy Loss of Gluons, Baryons and k-Quarks in an N=4 SYM Plasma

We consider different types of external color sources that move through a strongly-coupled thermal N=4 super-Yang-Mills plasma, and calculate, via the AdS/CFT correspondence, the dissipative force (or equivalently, the rate of energy loss) they experience. A bound state of k quarks in the totally antisymmetric representation is found to feel a force with a nontrivial k-dependence. Our result for k=1 (or k=N-1) agrees at large N with the one obtained recently by Herzog et al. and Gubser, but contains in addition an infinite series of 1/N corrections. The baryon (k=N) is seen to experience no drag. Finally, a heavy gluon is found to be subject to a force which at large N is twice as large as the one experienced by a heavy quark, in accordance with gauge theory expectations.Comment: Latex 2e, 24 pages, 1 eps figure; v2: slightly amplified discussion on the relation between the drag force and the tension of a spatial Wilson loop; v3: minor changes, version to appear in JHE

Clinical Instructor Perceptions of the Collaborative Clinical Education Model: Providing Solutions for Success in Physical Therapy Education

Purpose: The most common approach to physical therapy clinical education is the one-to-one (1:1) model. The collaborative clinical education model (CCEM) offers an alternative and beneficial approach to education but is not widely utilized within physical therapy. The primary aim of this study was to explore the experiences and perceptions of clinical instructors (CIs) teaching within the CCEM while also receiving structured support from an academic program. Methods: This study used semi-structured interviews before and after the CCEM experience to explore CI perceptions. CIs received formalized support that included pre-experience meetings, a CCEM Toolkit resource, scheduled follow-ups during the experience, and a post-clinical debriefing. Interview transcripts were analyzed using a qualitative data analysis program and collaborative coding process. Results: CIs’ perceptions of the CCEM shifted following participation. Participants noted a need to be prepared with appropriate teaching strategies, have frequent communication with the academic program, and have a supportive clinical environment. Conclusion: CI participation in the CCEM is challenged by negative perceptions and lack of experience with collaborative learning. CI perceptions of the CCEM can become more positive after actually teaching in the CCEM; therefore, perceived challenges need to be addressed to increase CI participation. The CCEM may be more widely accepted if CIs’ perceived challenges are addressed in partnership with an academic program with intentional CCEM training and support strategies

Discourse comprehension in L2: Making sense of what is not explicitly said

Using ERPs, we tested whether L2 speakers can integrate multiple sources of information (e.g., semantic, pragmatic information) during discourse comprehension. We presented native speakers and L2 speakers with three-sentence scenarios in which the final sentence was highly causally related, intermediately related, or causally unrelated to its context; its interpretation therefore required simple or complex inferences. Native speakers revealed a gradual N400-like effect, larger in the causally unrelated condition than in the highly related condition, and falling in-between in the intermediately related condition, replicating previous results. In the crucial intermediately related condition, L2 speakers behaved like native speakers, however, showing extra processing in a later time-window. Overall, the results show that, when reading, L2 speakers are able to process information from the local context and prior information (e.g., world knowledge) to build global coherence, suggesting that they process different sources of information to make inferences online during discourse comprehension, like native speakers.This work was supported by grants from the Spanish Government (PSI2011-23033, CONSOLIDER-INGENIO2010 CSD2007-00048, ECO2011-25295, and ECO2010-09555-E), from the Catalan Government (SGR 2009-1521) and from the Grup de Recerca en Neurociència Cognitiva (GRNC) - 2014SGR1210. It has also received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no. 613465

Imagining a Polyvocal Prison Image Archive: Dialogical photography and the aesthetics of ethics in spaces of incarceration

Working creatively and collaboratively with photography in a prison is ethically fraught, due to the historical symbiosis of prisons and photography, and the stark inequity between incarcerated and non-incarcerated people. This practice-based research project explores methods for turning towards and articulating these challenges asking: What new ways of working with photography emerge from the collaborative creation of a photographic archive with imprisoned people? And, drawing on artist Walead Beshty (2015): How does the social and ethical context in which collaborative photography takes place become visible? I take Ariella Azoulay’s work (2019) on the interactions surrounding the photographic moment, and Tina Campt’s approach of ‘listening to images’ (2017) as starting points for addressing these questions. During a year-long series of workshops with imprisoned people at HMP Dumfries in Southwest Scotland, we collected, generated, curated, and discussed images reflecting aspects of the prison that co-creators felt should be remembered. We developed a dialogical, para-archival approach (Slager, 2015) that presents aesthetic logic as an alternative to the illogicality of the prison. Installing and documenting artwork in the prison was key, bringing creative practice into conversation with institutional space. The outcome is a layered, polyvocal record of a place. It is also a collaborative meditation on what it is to record, to document, to create and co-create, and what it means to do so whilst imprisoned. The nuances of the collaboration are captured through an ethical framework, through my reflection on roles and collaborative modes (facilitated by audio recordings of workshops) and through the artwork itself. Each of these elements was the subject of detailed discussion with co-creators and their contributions crucially informed my understanding of the research project. The impact of the prison environment on the collaborative process and the images we produced was all-pervasive, but the project opened an interstice, a small space 8 for creativity and collaboration. Crucially however, the value of projects like this is in both making space for and visualising something that imprisoned people are already experts in, that is the daily practices of creativity, hope and aesthetics that are essential for survival in prison (Fleetwood, 2020, Kelly, 2022). This research project makes an original argument for the potential value of collaborations between incarcerated and non-incarcerated artists, which is in making space for the practice of the interstice. Turning towards ethical challenges can lead to new understandings of photography and power in the prison. The significance of this work is in interrogating methods for placing ethical complexity at the centre of a collaborative art project, and articulating the nuances of the process. This should be of interest to those pursuing collaborative research in the arts and social sciences, and more specifically to artists working with participatory photography

A study of the preschool child's concept of race based upon an analysis of the child's picture interpretation

Call number: LD2668 .T4 1949 B4

Holographic second laws of black hole thermodynamics

Recently, it has been shown that for out-of-equilibrium systems, there are additional constraints on thermodynamical evolution besides the ordinary second law. These form a new family of second laws of thermodynamics, which are equivalent to the monotonicity of quantum R\'enyi divergences. In black hole thermodynamics, the usual second law is manifest as the area increase theorem. Hence one may ask if these additional laws imply new restrictions for gravitational dynamics, such as for out-of-equilibrium black holes? Inspired by this question, we study these constraints within the AdS/CFT correspondence. First, we show that the R\'enyi divergence can be computed via a Euclidean path integral for a certain class of excited CFT states. Applying this construction to the boundary CFT, the R\'enyi divergence is evaluated as the renormalized action for a particular bulk solution of a minimally coupled gravity-scalar system. Further, within this framework, we show that there exist transitions which are allowed by the traditional second law, but forbidden by the additional thermodynamical constraints. We speculate on the implications of our findings.Comment: 81 pages, 19 figures; v2: clarifications and reference added, minor typos corrected, published versio

Incidence and phenotypes of childhood-onset genetic epilepsies:a prospective population-based national cohort

Epilepsy is common in early childhood. In this age group it is associated with high rates of therapy-resistance, and with cognitive, motor, and behavioural comorbidity. A large number of genes, with wide ranging functions, are implicated in its aetiology, especially in those with therapy-resistant seizures. Identifying the more common single-gene epilepsies will aid in targeting resources, the prioritization of diagnostic testing and development of precision therapy. Previous studies of genetic testing in epilepsy have not been prospective and population-based. Therefore, the population-incidence of common genetic epilepsies remains unknown. The objective of this study was to describe the incidence and phenotypic spectrum of the most common single-gene epilepsies in young children, and to calculate what proportion are amenable to precision therapy. This was a prospective national epidemiological cohort study. All children presenting with epilepsy before 36 months of age were eligible. Children presenting with recurrent prolonged (>10 min) febrile seizures; febrile or afebrile status epilepticus (>30 min); or with clusters of two or more febrile or afebrile seizures within a 24-h period were also eligible. Participants were recruited from all 20 regional paediatric departments and four tertiary children’s hospitals in Scotland over a 3-year period. DNA samples were tested on a custom-designed 104-gene epilepsy panel. Detailed clinical information was systematically gathered at initial presentation and during follow-up. Clinical and genetic data were reviewed by a multidisciplinary team of clinicians and genetic scientists. The pathogenic significance of the genetic variants was assessed in accordance with the guidelines of UK Association of Clinical Genetic Science (ACGS). Of the 343 patients who met inclusion criteria, 333 completed genetic testing, and 80/333 (24%) had a diagnostic genetic finding. The overall estimated annual incidence of single-gene epilepsies in this well-defined population was 1 per 2120 live births (47.2/100 000; 95% confidence interval 36.9–57.5). PRRT2 was the most common single-gene epilepsy with an incidence of 1 per 9970 live births (10.0/100 000; 95% confidence interval 5.26–14.8) followed by SCN1A: 1 per 12 200 (8.26/100 000; 95% confidence interval 3.93–12.6); KCNQ2: 1 per 17 000 (5.89/100 000; 95% confidence interval 2.24–9.56) and SLC2A1: 1 per 24 300 (4.13/100 000; 95% confidence interval 1.07–7.19). Presentation before the age of 6 months, and presentation with afebrile focal seizures were significantly associated with genetic diagnosis. Single-gene disorders accounted for a quarter of the seizure disorders in this cohort. Genetic testing is recommended to identify children who may benefit from precision treatment and should be mainstream practice in early childhood onset epilepsy

Building on Progress Towards Fair Access : annual report 2019

Supplementary Table 3: Anti-epileptic drug use in patients with SYNGAP1 mutations or deletion