title: Cause of pulse artefacts inherent to the electrodes of neuromodulation implants

authors: Single, Peter

abstract: The current pulses delivered through platinum electrodes by medical implants to recruit neurones give rise to slowly-decaying voltage tails, called "artefacts''. These tails make measurement of evoked potentials following the pulses very difficult. We present evidence to show that in a typical clinical scenario these tails are mostly caused by concentration gradients of species induced in the electrical double layer adsorbed onto the surface of both stimulating and passive electrodes. A compact model is presented that allows simulation of these artefacts. The model is verified against measurements made in saline. This shows that electrode artefacts are an intrinsic property of the conductive electrodes of a lead.

text: Cause of pulse artefacts inherent to the electrodes of neuromodulation implants The current pulses delivered through platinum electrodes by medical implants to recruit neurones give rise to slowly-decaying voltage tails, called "artefacts''. These tails make measurement of evoked potentials following the pulses very difficult. We present evidence to show that in a typical clinical scenario these tails are mostly caused by concentration gradients of species induced in the electrical double layer adsorbed onto the surface of both stimulating and passive electrodes. A compact model is presented that allows simulation of these artefacts. The model is verified against measurements made in saline. This shows that electrode artefacts are an intrinsic property of the conductive electrodes of a lead.

year: 2018

title: The response of a floating ice sheet to an accelerating line load

authors: Miles, J.

abstract: The two-dimensional response of a thin, floating sheet of ice to a line load that accelerates from rest at $t = 0$ to a uniform velocity V for $t \geq T$ is determined through an integral-transform solution of the linearized equations of motion. If $T = 0$ – i.e. if the load is impulsively started with velocity V – the solution exhibits singularities at $V = c_0$, the shallow-water-gravity-wave speed, and $V = c_{\min}$, the minimum speed for transverse motion of the ice, but these singularities are avoided by the acceleration of the load through the critical speeds.

text: The response of a floating ice sheet to an accelerating line load The two-dimensional response of a thin, floating sheet of ice to a line load that accelerates from rest at $t = 0$ to a uniform velocity V for $t \geq T$ is determined through an integral-transform solution of the linearized equations of motion. If $T = 0$ – i.e. if the load is impulsively started with velocity V – the solution exhibits singularities at $V = c_0$, the shallow-water-gravity-wave speed, and $V = c_{\min}$, the minimum speed for transverse motion of the ice, but these singularities are avoided by the acceleration of the load through the critical speeds.

year: 2003

title: Dialogue as a method for evolving Mātauranga Māori: Perspectives on the use of embryos in research

authors: Hudson, Maui

subjects: New Zealand

abstract: This paper explores the epistemological divide between mātauranga Māori (Māori knowledge) and science, and considers which cultural concepts have relevance when considering the use of embryos in research. We argue that empowerment is a necessary precursor for a dialogue process to be effective and to maintain the cultural dignity and confidence of the participants. Negotiating spaces to share ideas, concepts and values between different knowledge systems is an important exercise that creates opportunities for innovative thinking. The identification of cultural cues and indigenous reference points for considering how knowledge relating to embryo research might be located within a traditional knowledge schema is a necessary type of activity to ensure mātauranga Māori maintains its usefulness for Māori in a changing society while retaining its indigenous spirit and cultural tradition.

text: Dialogue as a method for evolving Mātauranga Māori: Perspectives on the use of embryos in research This paper explores the epistemological divide between mātauranga Māori (Māori knowledge) and science, and considers which cultural concepts have relevance when considering the use of embryos in research. We argue that empowerment is a necessary precursor for a dialogue process to be effective and to maintain the cultural dignity and confidence of the participants. Negotiating spaces to share ideas, concepts and values between different knowledge systems is an important exercise that creates opportunities for innovative thinking. The identification of cultural cues and indigenous reference points for considering how knowledge relating to embryo research might be located within a traditional knowledge schema is a necessary type of activity to ensure mātauranga Māori maintains its usefulness for Māori in a changing society while retaining its indigenous spirit and cultural tradition.

year: 2010