64 research outputs found
A preliminary analysis and model of prostate injection distributions
PURPOSE. Understanding the internal dynamics of prostate injections, particularly injection pattern distribution is a key step to developing new therapies for prostate disease that may be best served with a direct injection approach. Due to excellent properties involving liquid contrast agents, MRI can be used for targeting and monitoring of injections into organs and tissues. MATERIALS AND METHODS. Eleven intraprostatic injections were performed in vivo with canines using a custom transrectal guiding and imaging system for use in a standard 1.5 T MR scanner. In addition, 25 injections were performed on excised cadaveric human prostates, using a MedRad Spectris⹠injector system. MRI was used to guide the injections and monitor intraparenchymal injection distribution. RESULTS. T1 and T2-weighted MR images were correlated with histology to produce three-dimensional data sets that can be used to analyze trends in injection patterns. This analysis was used to develop strategies for injection prediction such as gadolinium preinjections and diffusion-weighted imaging guidance. In addition, a rough model of prostate injections is described, and a preliminary injection guide is developed that takes into account the individual clinician's goals for therapy. CONCLUSIONS. MR visualization of injected therapeutic agents allows for prediction and monitoring of drug distributions, possibly improving efficacy and reducing side effects. Injection analysis and modeling may be used to assist in optimizing clinical treatments that require or would benefit from focal parenchymal injections into the prostate. © 2005 Wiley-Liss, Inc
Sound Synthesis with Auditory Distortion Products
This article describes methods of sound synthesis based on auditory distortion products, often called combination tones. In 1856, Helmholtz was the first to identify sum and difference tones as products of auditory distortion. Today this phenomenon is well studied in the context of otoacoustic emissions, and the âdistortionâ is understood as a product of what is termed the cochlear amplifier. These tones have had a rich history in the music of improvisers and drone artists. Until now, the use of distortion tones in technological music has largely been rudimentary and dependent on very high amplitudes in order for the distortion products to be heard by audiences. Discussed here are synthesis methods to render these tones more easily audible and lend them the dynamic properties of traditional acoustic sound, thus making auditory distortion a practical domain for sound synthesis. An adaptation of single-sideband synthesis is particularly effective for capturing the dynamic properties of audio inputs in real time. Also presented is an analytic solution for matching up to four harmonics of a target spectrum. Most interestingly, the spatial imagery produced by these techniques is very distinctive, and over loudspeakers the normal assumptions of spatial hearing do not apply. Audio examples are provided that illustrate the discussion
Education: Expectation and the Unexpected
In this paper I consider the concept of expectation in Higher Education. To focus the discussion I begin by sketching out some examples of how this notion pervades a number of practices in the university, and how in particular, expectation drives the way that the university tutorial operates between tutors and students. In relating this to the tendency towards what has been identified as the marketization and consumerism of higher education, I draw on the distinction that Paul Standish identifies between and âeconomy of exchangeâ and an âeconomy of excessâ, and suggest how expectation and responsibility figure in these economies. In moving to think beyond narrow conceptions of expectation and responsibility, and beyond the literature on policy and management in higher education, I turn to the work of the Jewish philosophers, Martin Buber and Emmanuel Levinas to show how they have both given attention to richer ideas of relationship, responsibility and the other. I initially outline Buberâs central work on the distinction between I-It and I-Thou modes of relationship, and how the latter is characterised by a dialogic intersubjectivity. I contrast this with the work of Emmanuel Levinas and draw out the distinction between the mutuality at the heart of Buberâs work, and the relationship of asymmetry that markâs Levinasâ conception of our responsibility to the other, which is ethics. Having drawn the distinction, I then show how there are lines of connection in their respective philosophical projects, specifically how speech or dialogue is central to the relationship with the other in both thinkers. I find in both Buber and Levinas that speech cannot be thought of solely as communication. This has significant implications for education: speech is not simply the communication of (curricular) content between tutor and student. Given this, teaching can be thought of as a space for encounter with the other through language. This has further implications for thinking about the place of the tutorial in a university education. At this point I return to the scene of the university tutorial and suggest that, rather than seeing it as a place only for the meeting of expectations (which would suggest a closed economy of exchange), it might be envisioned as a space for encounter with the unexpected. In considering the nature of the encounter in relation to an example from the film adaptation of Alan Bennettâs The History Boys, I argue that the tutorial opens up the possibility for a mutual encounter with otherness. This positions the tutorial as a space of educational otherness, - a Foucauldian heterotopia which rejects the expectation-bound economy of exchange, and which offers instead the possibility of an education marked instead by an economy of excess. <br/
Embodied Musical Interaction
Music is a natural partner to human-computer interaction, offering tasks and use cases for novel forms of interaction. The richness of the relationship between a performer and their instrument in expressive musical performance can provide valuable insight to human-computer interaction (HCI) researchers interested in applying these forms of deep interaction to other fields. Despite the longstanding connection between music and HCI, it is not an automatic one, and its history arguably points to as many differences as it does overlaps. Music research and HCI research both encompass broad issues, and utilize a wide range of methods. In this chapter I discuss how the concept of embodied interaction can be one way to think about music interaction. I propose how the three âparadigmsâ of HCI and three design accounts from the interaction design literature can serve as a lens through which to consider types of music HCI. I use this conceptual framework to discuss three different musical projectsâHaptic Wave, Form Follows Sound, and BioMuse
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