4,785 research outputs found
Interfacing peripheral nerve with macro-sieve electrodes following spinal cord injury
Macro-sieve electrodes were implanted in the sciatic nerve of five adult male Lewis rats following spinal cord injury to assess the ability of the macro-sieve electrode to interface regenerated peripheral nerve fibers post-spinal cord injury. Each spinal cord injury was performed via right lateral hemisection of the cord at the T9â10 site. Five months post-implantation, the ability of the macro-sieve electrode to interface the regenerated nerve was assessed by stimulating through the macro-sieve electrode and recording both electromyography signals and evoked muscle force from distal musculature. Electromyography measurements were recorded from the tibialis anterior and gastrocnemius muscles, while evoked muscle force measurements were recorded from the tibialis anterior, extensor digitorum longus, and gastrocnemius muscles. The macro-sieve electrode and regenerated sciatic nerve were then explanted for histological evaluation. Successful sciatic nerve regeneration across the macro-sieve electrode interface following spinal cord injury was seen in all five animals. Recorded electromyography signals and muscle force recordings obtained through macro-sieve electrode stimulation confirm the ability of the macro-sieve electrode to successfully recruit distal musculature in this injury model. Taken together, these results demonstrate the macro-sieve electrode as a viable interface for peripheral nerve stimulation in the context of spinal cord injury
An Intelligent Fuse-box for use with Renewable Energy Sources integrated within a Domestic Environment
This paper outlines a proposal for an intelligent fuse-box that can replace existing fuse-boxes in a domestic context such that a number of renewable energy sources can easily be integrated into the domestic power supply network, without the necessity for complex islanding and network protection. The approach allows intelligent control of both the generation of power and its supply to single or groups of electrical appliances. Energy storage can be implemented in such a scheme to even out the power supplied and simplify the control scheme required, and environmental monitoring and load analysis can help in automatically controlling the supply and demand profiles for optimum electrical and economic efficiency. Simulations of typical scenarios are carried out to illustrate the concept in operation
The Promise and Peril of Walking Indigenous Territorial Recognitions carried out by Settlers
This article proposes that if the permission and guidance of local Indigenous groups is obtained, and their protocols observed, a collaborative physical act of settler, or Indigenous-settler walking across territory on which events are to be held may constitute a more constructive form of âterritorial acknowledgementâ than a verbal statement read out at such an event. By drawing sustained attention not only to Indigenous land but also to Indigenous title, resources, and jurisdiction, and by pointedly underlining the actual land in question, walking territorial acknowledgements can help settlers to develop an embodied sense of place-in-relation. In so doing they can move forward both the relationality implicit in Indigenous territorial recognition and the claims territorial recognitions make on settler bodies. These walk-acts diminish the superficial âvirtue-signallingâ and public performance of contrition which too often attach to such acknowledgements, threatening to render them obsolete
Moving from the Archive: Historiography and "Authenticity" in Commedia dell'Arte Performance
This dissertation examines the multiple definitions of âCommedia dellâArteâ in historiography and contemporary performance, analyzing potentials and problematics behind attempts to understand âhistoricalâ Commedia dellâArte and to (re)construct contemporary Commedia using what Franklin J. Hildy calls an âapplied theater historyâ approach. Employing archival historiography, literary analysis, art historical techniques, practical dramaturgy, Practice-as-Research, and qualitative research, I describe different realities of Commedia dellâArte performance from history and contemporary practice, including ways in which âmistakesâ or âappropriationsâ in the form have become included within its present identities.
Chapter One describes the status of the field, problems, and approaches to identifying what Commedia dellâArte âisâ today based upon autoethnography and interview material from contemporary practitioners, whose competing approaches inform the ongoing conversation. Chapter Two traces the history of the form known as âCommedia dellâArteâ from its origins to contemporary pedagogy with special attention given to appropriations, evolutions, distortions, and efforts at reproduction. In Chapter Three, I narrow the focus to a specific case-studyâa recent production of the classic scenario Il Cavadente (The Tooth-Puller) from the Commedia dellâArte repertoireâwith special attention to the problematics of translating, interpreting, and reconstructing historical sources as dramatic literary content. Chapter Four describes an art-historical approach to assessing, analyzing, and utilizing iconography from Commedia dellâArteâs history, while Chapter Five describes a specific attempt to design the visual world for a contemporary production of The Tooth-Puller with reference to competing goals of faithfulness to the tradition and availability for artistic innovation. Chapter Six employs Practice-as-Research (and what I advocate as Research-as-Practice) to embody reimagined characters based on the Commedia archive. Chapter Seven utilizes participant interviews and audience surveys to reflect upon Ole Miss Theatre & Filmâs production of The Tooth-Puller, the final (though always fluid) script of which is included as Appendix A. This concluding chapter also reflects, through the voices of contemporary teachers and practitioners, on the nature of Commedia dellâArte and its place in current actor training and theatrical innovation.
While the field of Commedia practitioners today is divided between those who prescribe an âauthenticâ system for âhistoricalâ Commedia and those who freely declare that âCommedia doesnât existâ in any knowable form, this dissertation models a middle way of interacting faithfully and rigorously with extant data from the past in order to freely create a continuation of the Commedia tradition for the future
Bayesian Online Learning of the Hazard Rate in Change-Point Problems
Change-point models are generative models of time-varying data in which the underlying generative parameters undergo discontinuous changes at different points in time known as change points. Changepoints often represent important events in the underlying processes, like a change in brain state reflected in EEG data or a change in the value of a company reflected in its stock price. However, change-points can be difficult to identify in noisy data streams. Previous attempts to identify change-points online using Bayesian inference relied on specifying in advance the rate at which they occur, called the hazard rate (h). This approach leads to predictions that can depend strongly on the choice of h and is unable to deal optimally with systems in which h is not constant in time. In this letter, we overcome these limitations by developing a hierarchical extension to earlier models. This approach allows h itself to be inferred from the data, which in turn helps to identify when change-points occur. We show that our approach can effectively identify change-points in both toy and real data sets with complex hazard rates and how it can be used as an ideal-observermodel for human and animal behavior when faced with rapidly changing inputs
High order magnon bound states in the quasi-one-dimensional antiferromagnet -NaMnO
Here we report on the formation of two and three magnon bound states in the
quasi-one-dimensional antiferromagnet -NaMnO, where the single-ion,
uniaxial anisotropy inherent to the Mn ions in this material provides a
binding mechanism capable of stabilizing higher order magnon bound states.
While such states have long remained elusive in studies of antiferromagnetic
chains, neutron scattering data presented here demonstrate that higher order
composite magnons exist, and, specifically, that a weak three-magnon
bound state is detected below the antiferromagnetic ordering transition of
NaMnO. We corroborate our findings with exact numerical simulations of a
one-dimensional Heisenberg chain with easy-axis anisotropy using matrix-product
state techniques, finding a good quantitative agreement with the experiment.
These results establish -NaMnO as a unique platform for exploring
the dynamics of composite magnon states inherent to a classical
antiferromagnetic spin chain with Ising-like single ion anisotropy.Comment: 5 pages, 4 figure
Spectroscopic Transit Search: a self-calibrating method for detecting planets around bright stars
We search for transiting exoplanets around the star Pictoris using
high resolution spectroscopy and Doppler imaging that removes the need for
standard star observations. These data were obtained on the VLT with UVES
during the course of an observing campaign throughout 2017 that monitored the
Hill sphere transit of the exoplanet Pictoris b. We utilize line
profile tomography as a method for the discovery of transiting exoplanets. By
measuring the exoplanet distortion of the stellar line profile, we remove the
need for reference star measurements. We demonstrate the method with white
noise simulations, and then look at the case of Pictoris, which is a
Scuti pulsator. We describe a method to remove the stellar pulsations
and perform a search for any transiting exoplanets in the resultant data set.
We inject fake planet transits with varying orbital periods and planet radii
into the spectra and determine the recovery fraction. In the photon noise
limited case we can recover planets down to a Neptune radius with an 80%
success rate, using an 8 m telescope with a spectrograph and 20
minutes of observations per night. The pulsations of Pictoris limit our
sensitivity to Jupiter-sized planets, but a pulsation removal algorithm
improves this limit to Saturn-sized planets. We present two planet candidates,
but argue that their signals are most likely caused by other phenomena. We have
demonstrated a method for searching for transiting exoplanets that (i) does not
require ancillary calibration observations, (ii) can work on any star whose
rotational broadening can be resolved with a high spectral dispersion
spectrograph and (iii) provides the lowest limits so far on the radii of
transiting Jupiter-sized exoplanets around Pictoris with orbital
periods from 15 days to 200 days with >50% coverage.Comment: Accepted for publication in A&A, 8 pages, 8 figures. The Github
repository can be found at
https://github.com/lennartvansluijs/Spectroscopic-Transit-Searc
Transfer of the brachialis to the anterior interosseous nerve as a treatment strategy for cervical spinal cord injury: Technical note
Study DesignâTechnical report. ObjectiveâTo provide a technical description of the transfer of the brachialis to the anterior interosseous nerve (AIN) for the treatment of tetraplegia after a cervical spinal cord injury (SCI). MethodsâIn this technical report, the authors present a case illustration of an ideal surgical candidate for a brachialis-to-AIN transfer: a 21-year-old patient with a complete C7 spinal cord injury and failure of any hand motor recovery. The authors provide detailed description including images and video showing how to perform the brachialis-to-AIN transfer. ResultsâThe brachialis nerve and AIN fascicles can be successfully isolated using visual inspection and motor mapping. Then, careful dissection and microsurgical coaptation can be used for a successful anterior interosseous reinnervation. ConclusionâThe nerve transfer techniques for reinnervation have been described predominantly for the treatment of brachial plexus injuries. The majority of the nerve transfer techniques have focused on the upper brachial plexus or distal nerves of the lower brachial plexus. More recently, nerve transfers have reemerged as a potential reinnervation strategy for select patients with cervical SCI. The brachialis-to-AIN transfer technique offers a potential means for restoration of intrinsic hand function in patients with SCI
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