752 research outputs found
Non-reciprocal interactions spatially propagate fluctuations in a 2D Ising model
Motivated by the anisotropic interactions between fish, we implement
spatially anisotropic and therefore non-reciprocal interactions in the 2D Ising
model. First, we show that the model with non-reciprocal interactions alters
the system critical temperature away from that of the traditional 2D Ising
model. Further, local perturbations to the magnetization in this
out-of-equilibrium system manifest themselves as traveling waves of spin states
along the lattice, also seen in a mean-field model of our system. The speed and
directionality of these traveling waves are controllable by the orientation and
magnitude of the non-reciprocal interaction kernel as well as the proximity of
the system to the critical temperature.Comment: 4 figure
Dynamics & Predictions in the Co-Event Interpretation
Sorkin has introduced a new, observer independent, interpretation of quantum
mechanics that can give a successful realist account of the 'quantum
microworld' as well as explaining how classicality emerges at the level of
observable events for a range of systems including single time 'Copenhagen
measurements'. This 'co-event interpretation' presents us with a new ontology,
in which a single 'co-event' is real. A new ontology necessitates a review of
the dynamical & predictive mechanism of a theory, and in this paper we begin
the process by exploring means of expressing the dynamical and predictive
content of histories theories in terms of co-events.Comment: 35 pages. Revised after refereein
Entropy Production Rate is Maximized in Non-Contractile Actomyosin
The actin cytoskeleton is an active semi-flexible polymer network whose
non-equilibrium properties coordinate both stable and contractile behaviors to
maintain or change cell shape. While myosin motors drive the actin cytoskeleton
out-of-equilibrium, the role of myosin-driven active stresses in the
accumulation and dissipation of mechanical energy is unclear. To investigate
this, we synthesize an actomyosin material in vitro whose active stress content
can tune the network from stable to contractile. Each increment in activity
determines a characteristic spectrum of actin filament fluctuations which is
used to calculate the total mechanical work and the production of entropy in
the material. We find that the balance of work and entropy does not increase
monotonically and, surprisingly, the entropy production rate is maximized in
the non-contractile, stable state. Our study provides evidence that the origins
of system entropy production and activity-dependent dissipation arise from
disorder in the molecular interactions between actin and myosinComment: 31 pages, 5 figure
Heidelberg standard examination and "Heidelberg standard procedures" - Development of faculty-wide standards for physical examination techniques and clinical procedures in undergraduate medical education
The competent physical examination of patients and the safe and professional implementation of clinical procedures constitute essential components of medical practice in nearly all areas of medicine. The central objective of the projects "Heidelberg standard examination" and "Heidelberg standard procedures", which were initiated by students, was to establish uniform interdisciplinary standards for physical examination and clinical procedures, and to distribute them in coordination with all clinical disciplines at the Heidelberg University Hospital. The presented project report illuminates the background of the initiative and its methodological implementation. Moreover, it describes the multimedia documentation in the form of pocketbooks and a multimedia internet-based platform, as well as the integration into the curriculum. The project presentation aims to provide orientation and action guidelines to facilitate similar processes in other faculties
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This Article Corrects: “Assessment of Physician Well-being, Part Two: Beyond Burnout”
Part One of this two-article series reviews assessment tools to measure burnout and other negative states. Physician well-being goes beyond merely the absence of burnout. Transient episodes of burnout are to be expected. Measuring burnout alone is shortsighted. Well-being includes being challenged, thriving, and achieving success in various aspects of personal and professional life. In this second part of the series, we identify and describe assessment tools related to wellness, quality of life, resilience, coping skills, and other positive states
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