Distribution of motor unit potential velocities in short static and prolonged dynamic contractions at low forces: use of the within-subject’s skewness and standard deviation variables

Behaviour of motor unit potential (MUP) velocities in relation to (low) force and duration was investigated in biceps brachii muscle using a surface electrode array. Short static tests of 3.8 s (41 subjects) and prolonged dynamic tests (prolonged tests) of 4 min (30 subjects) were performed as position tasks, applying forces up to 20% of maximal voluntary contraction (MVC). Four variables, derived from the inter-peak latency technique, were used to describe changes in the surface electromyography signal: the mean muscle fibre conduction velocity (CV), the proportion between slow and fast MUPs expressed as the within-subject skewness of MUP velocities, the within-subject standard deviation of MUP velocities [SD-peak velocity (PV)], and the amount of MUPs per second (peak frequency = PF). In short static tests and the initial phase of prolonged tests, larger forces induced an increase of the CV and PF, accompanied with the shift of MUP velocities towards higher values, whereas the SD-PV did not change. During the first 1.5–2 min of the prolonged lower force levels tests (unloaded, and loaded 5 and 10% MVC) the CV and SD-PV slightly decreased and the MUP velocities shifted towards lower values; then the three variables stabilized. The PF values did not change in these tests. However, during the prolonged higher force (20% MVC) test, the CV decreased and MUP velocities shifted towards lower values without stabilization, while the SD-PV broadened and the PF decreased progressively. It is argued that these combined results reflect changes in both neural regulatory strategies and muscle membrane state

The public and agricultural biotechnology: key questions

Biotechnology is a commitment to myth. By refusing to acknowledge the superstition implied in our blind adherence to our vision of a world of bliss, we move deeper into a chaos from which life itself may be unable to recover

Ethical Storytelling: How Ethical Guidelines Across Canada are Responding to (or Failing to Respond to) Advancements in Multimedia Tools

This thesis explores the intersection of advancements in multimedia technology and the role of ethics guidelines in Canadian journalism. This thesis uses a quantitative content analysis and semi-structured interviews to build on how virtue ethics, deontology, and utilitarianism interact with the codes of conduct of a sample of Canadian media outlets. This thesis concludes that there are some ethical issues that are arising from new technologies that some journalists identified as outside of the conventional boundaries of ethics guidelines. It identifies that through the multiple ethical systems working in coordination with one another, organizations can provide their journalists with resources to address the changing technological landscape. This thesis also identifies that a considered reliance on virtue-based ethics will work to future-proof journalism against possible ethical issues related to advancements in multimedia technology