252 research outputs found
Sound Waves in (2+1) Dimensional Holographic Magnetic Fluids
We use the AdS/CFT correspondence to study propagation of sound waves in
strongly coupled (2+1) dimensional conformal magnetic fluids. Our computation
provides a nontrivial consistency check of the viscous magneto-hydrodynamics of
Hartnoll-Kovtun-Muller-Sachdev to leading order in the external field.
Depending on the behavior of the magnetic field in the hydrodynamic limit, we
show that it can lead to further attenuation of sound waves in the (2+1)
dimensional conformal plasma, or reduce the speed of sound. We present both
field theory and dual supergravity descriptions of these phenomena. While to
the leading order in momenta the dispersion of the sound waves obtained from
the dual supergravity description agrees with the one predicted from field
theory, we find a discrepancy at higher order. This suggests that further
corrections to HKMS magneto-hydrodynamics are necessary.Comment: 32 pages, LaTeX; minor corrections, references added; an error in the
boundary conditions fixed, a slight change in the result
Supersymmetry Breaking from a Calabi-Yau Singularity
We conjecture a geometric criterion for determining whether supersymmetry is
spontaneously broken in certain string backgrounds. These backgrounds contain
wrapped branes at Calabi-Yau singularites with obstructions to deformation of
the complex structure. We motivate our conjecture with a particular example:
the quiver gauge theory corresponding to a cone over the first del
Pezzo surface, . This setup can be analyzed using ordinary supersymmetric
field theory methods, where we find that gaugino condensation drives a
deformation of the chiral ring which has no solutions. We expect this breaking
to be a general feature of any theory of branes at a singularity with a smaller
number of possible deformations than independent anomaly-free fractional
branes.Comment: 32 pages, 6 figures, latex, v2: minor changes, refs adde
State of the Art in Building Façades
This chapter presents a portfolio of building materials suitable for facades. It describes the relationship between material type, building element, facade, and the entire building structure. Traditional facades based on static components, as well as adaptive concepts able to interact with changing environmental conditions, are briefly described and illustrated with pictures. Climatic design principles, biomimicry, and bioinspiration in architecture are introduced with the purpose of inspiring future developments
Lepton anomalous magnetic moments - a theory update
Standard Model contributions to the electron, muon, and tau lepton anomalous
magnetic moments, a_l=(g_l-2)/2, are reviewed and updated. The fine structure
constant is obtained from the electron g_e-2 and used to refine the QED
contribution to the muon g_mu-2. Recent advances in electroweak and hadronic
effects on g_mu-2 are summarized. Examples of ``New Physics'' probed by the
a_mu Brookhaven experiment E821 are outlined. The prediction for a_tau is also
given.Comment: 8 pages; invited talk at the 5th International Workshop on Tau Lepton
Physics (Tau'98), September 1998, Santander, Spai
Field study of transit time through compacted clays : interim annual report
Interim annual report, July 1, 1989 to June 30, 1990Ope
Bounding Anomalous Gauge-Boson Couplings
In this version we have corrected some minor errors in the tables, corrected
typos, and added a reference. We have also updated our comparison with earlier
workers. Figures are now included as uuencoded compressed tar files.Comment: 32 page
1/N Effects in Non-Relativistic Gauge-Gravity Duality
We argue that higher-curvature terms in the gravitational Lagrangian lead,
via non-relativistic gauge-gravity duality, to finite renormalization of the
dynamical exponent of the dual conformal field theory. Our argument includes a
proof of the non-renormalization of the Schrodinger and Lifshitz metrics beyond
rescalings of their parameters, directly generalizing the AdS case. We use this
effect to construct string-theory duals of non-relativistic critical systems
with non-integer dynamical exponents, then use these duals to predict the
viscosity/entropy ratios of these systems. The predicted values weakly violate
the KSS bound.Comment: 26 pages, late
The Symptom Monitoring with Feedback Trial (SWIFT):protocol for a registry‑based cluster randomised controlled trial in haemodialysis
BACKGROUND: Kidney failure prevalence is increasing worldwide. Haemodialysis, peritoneal dialysis or kidney transplantation are undertaken to extend life with kidney failure. People receiving haemodialysis commonly experience fatigue, pain, nausea, cramping, itching, sleeping difficulties, anxiety and depression. This symptom burden contributes to poor health-related quality of life (QOL) and is a major reason for treatment withdrawal and death. The Symptom monitoring WIth Feedback Trial (SWIFT) will test the hypothesis that regular symptom monitoring with feedback to people receiving haemodialysis and their treating clinical team can improve QOL. METHODS: We are conducting an Australia and New Zealand Dialysis and Transplant (ANZDATA) registry-based cluster randomised controlled trial to determine the clinical- and cost-effectiveness at 12 months, of 3-monthly symptom monitoring using the Integrated Palliative Outcome Scale-Renal (IPOS-Renal) survey with clinician feedback, compared with usual care among adults treated with haemodialysis. Participants complete symptom scoring using a tablet, which are provided to participants and to clinicians. The trial aims to recruit 143 satellite haemodialysis centres, (up to 2400 participants). The primary outcome is change in health-related QOL, as measured by EuroQol 5-Dimension, 5-Level (EQ-5D-5L) instrument. Secondary outcomes include overall survival, symptom severity (including haemodialysis-associated fatigue), healthcare utilisation and cost-effectiveness. DISCUSSION: SWIFT is the first registry-based trial in the Australian haemodialysis population to investigate whether regular symptom monitoring with feedback to participants and clinicians improves QOL. SWIFT is embedded in the ANZDATA Registry facilitating pragmatic recruitment from public and private dialysis clinics, throughout Australia. SWIFT will inform future collection, storage and reporting of patient-reported outcome measures (PROMs) within a clinical quality registry. As the first trial to rigorously estimate the efficacy and cost-effectiveness of routine PROMs collection and reporting in haemodialysis units, SWIFT will provide invaluable information to health services, clinicians and researchers working to improve the lives of those with kidney failure. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12620001061921. Registered on 16 October 2020 SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13063-022-06355-0
The Influence of Feedback on Task-Switching Performance:A Drift Diffusion Modeling Account
Task-switching is an important cognitive skill that facilitates our ability to choose appropriate behavior in a varied and changing environment. Task-switching training studies have sought to improve this ability by practicing switching between multiple tasks. However, an efficacious training paradigm has been difficult to develop in part due to findings that small differences in task parameters influence switching behavior in a non-trivial manner. Here, for the first time we employ the Drift Diffusion Model (DDM) to understand the influence of feedback on task-switching and investigate how drift diffusion parameters change over the course of task switch training. We trained 316 participants on a simple task where they alternated sorting stimuli by color or by shape. Feedback differed in six different ways between subjects groups, ranging from No Feedback (NFB) to a variety of manipulations addressing trial-wise vs. Block Feedback (BFB), rewards vs. punishments, payment bonuses and different payouts depending upon the trial type (switch/non-switch). While overall performance was found to be affected by feedback, no effect of feedback was found on task-switching learning. Drift Diffusion Modeling revealed that the reductions in reaction time (RT) switch cost over the course of training were driven by a continually decreasing decision boundary. Furthermore, feedback effects on RT switch cost were also driven by differences in decision boundary, but not in drift rate. These results reveal that participants systematically modified their task-switching performance without yielding an overall gain in performance
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