2,850 research outputs found
Flexible surface electrodes targeting biopotential signals from forearm muscles for control of prosthetic hands: Part 1 - Characterisation of semg electrodes
This study is Part 1 of two studies which investigate the use of various flexible surface sensors as an alternative to the gold standard Ag/AgCl surface electromyography (sEMG) electrodes in identifying movement intention from a user during common hand gestures. Three conductive textiles, two commercial conductive elastomers and one E-skin elastomer produced on site were tested as biopotential electrodes to establish the efficacy of each in gathering movement intention from the human brain at the level of the muscle. Testing was performed in vivo on two participants across three hand gestures, with results demonstrating that sEMG electrodes made from a commercially sourced conductive fabric can outperform the traditional Ag/AgCl sEMG electrodes, obtaining substantially larger peak and RMS measurements. Given the disadvantages of Ag/AgCl electrodes over long usage periods, namely their tendency to dry out and significant skin preparation, resulting in variable impedances and skin irritation respectively, the incorporation of flexible surface EMG electrodes in hand prosthetic control systems would increase functionality of the prosthetic devices, consequently increasing the quality of life of prosthetic hand users
Ligand selectivity in stabilising tandem parallel folded G-quadruplex motifs in human telomeric DNA sequences
Biophysical studies of ligand interactions with three human telomeric repeat sequences (d(AGGG(TTAGGG)n, n = 3, 7 and 11)) show that an oxazole-based âclickâ ligand, which induces parallel folded quadruplexes, preferentially stabilises longer telomeric repeats providing evidence for selectivity in binding at the interface between tandem quadruplex motifs
Cognitive Computation sans Representation
The Computational Theory of Mind (CTM) holds that cognitive processes are essentially computational, and hence computation provides the scientific key to explaining mentality. The Representational Theory of Mind (RTM) holds that representational content is the key feature in distinguishing mental from non-mental systems. I argue that there is a deep incompatibility between these two theoretical frameworks, and that the acceptance of CTM provides strong grounds for rejecting RTM. The focal point of the incompatibility is the fact that representational content is extrinsic to formal procedures as such, and the intended interpretation of syntax makes no difference to the execution of an algorithm. So the unique 'content' postulated by RTM is superfluous to the formal procedures of CTM. And once these procedures are implemented in a physical mechanism, it is exclusively the causal properties of the physical mechanism that are responsible for all aspects of the system's behaviour. So once again, postulated content is rendered superfluous. To the extent that semantic content may appear to play a role in behaviour, it must be syntactically encoded within the system, and just as in a standard computational artefact, so too with the human mind/brain - it's pure syntax all the way down to the level of physical implementation. Hence 'content' is at most a convenient meta-level gloss, projected from the outside by human theorists, which itself can play no role in cognitive processing
Computation in Physical Systems: A Normative Mapping Account
The relationship between abstract formal procedures and the activities of actual physical systems has proved to be surprisingly subtle and controversial, and there are a number of competing accounts of when a physical system can be properly said to implement a mathematical formalism and hence perform a computation. I defend an account wherein computational descriptions of physical systems are high-level normative interpretations motivated by our pragmatic concerns. Furthermore, the criteria of utility and success vary according to our diverse purposes and pragmatic goals. Hence there is no independent or uniform fact to the matter, and I advance the âanti-realistâ conclusion that computational descriptions of physical systems are not founded upon deep ontological distinctions, but rather upon interest-relative human conventions. Hence physical computation is a âconventionalâ rather than a ânaturalâ kind
Factors associated with patient-reported outcomes following a humeral shaft fracture:Nonunion results in a poorer outcome despite union after surgical fixation
Beyond locutionary denotations: exploring trust between practitioners and policy
This study reports the findings of a research on the trust relationship between practitioners in the Skills for Life (SfL) area and the policy that informs their practice. The exploration of this relationship was premised on an extended notion of trust relationship which draws from the Speech Act theory of Austin (1962; Searle 1969; Kissine 2008), leading to the claim that the existence of different layers of imports in textual analysis makes it possible for a trust relationship to exist between the human/physical and the non human/non physical. The study found that the majority of practitioners in the SfL field trust policy to deliver its inherent policy only to a limited extent. Amongst others, the study identified the impact of the perlocutionary import of policy text on practitioners as a viable reason for this limited level of trust. Such perlocutionary imports, it also found, have adverse impact on practitioners who are considered to have drawn from previous experience to mediate the import of contemporary policies
Catalog of Nearby Isolated Galaxies in the Volume z<0.01
We present a catalog of 520 most isolated nearby galaxies with radial
velocities V_LG<3500 km/s covering the entire sky. This population of "space
orphans" makes up 4.8% among 10900 galaxies with measured radial velocities. We
describe the isolation criterion used to select our sample, called the "Local
Orphan Galaxies" (LOG), and discuss their basic optical and HI properties. A
half of the LOG catalog is occupied by the Sdm, Im and Ir morphological type
galaxies without a bulge. The median ratio M_gas/M_star in the LOG galaxies
exceeds 1. The distribution of the catalog galaxies on the sky looks uniform
with some signatures of a weak clustering on the scale of about 0.5 Mpc. The
LOG galaxies are located in the regions where the mean local density of matter
is approximately 50 times lower than the mean global density. We indicate a
number of LOG galaxies with distorted structures, which may be the consequence
of interaction of isolated galaxies with massive dark objects
Re-imagining the Borders of US Security after 9/11: Securitisation, Risk, and the Creation of the Department of Homeland Security
The articulation of international and transnational terrorism as a key issue in US security policy, as a result of the 9/11 attacks, has not only led to a policy rethink, it has also included a bureaucratic shift within the US, showing a re-thinking of the role of borders within US security policy. Drawing substantively on the 'securitisation' approach to security studies, the article analyses the discourse of US security in order to examine the founding of the Department of Homeland Security, noting that its mission provides a new way of conceptualising 'borders' for US national security. The securitisation of terrorism is, therefore, not only represented by marking terrorism as a security issue, it is also solidified in the organisation of security policy-making within the US state. As such, the impact of a 'war on terror' provides an important moment for analysing the re-articulation of what security is in the US, and, in theoretical terms, for reaffirming the importance of a relationship between the production of threat and the institutionalisation of threat response. © 2007 Taylor & Francis
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