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This study used an anaesthetized rat model to directly observe changes in diameter of the vessels supplying the sciatic nerve in response to acetylcholine ([10.sup.-4] M), a muscarinic receptor agonist, and atropine ([10.sup.- 5] M), a muscarinic receptor antagonist. Topical application of acetylcholine resulted in increases in vessel diameter (baseline: 22.0 [+ or -] 2.5 [micro]m, acetylcholine: 28.8 [+ or -] 3.3 [micro]m), while topical application of atropine resulted in a decrease in diameter (baseline: 26.6 [+ or -] 3.2 [micro]m, atropine: 15.5 [+ or -] 3.6 [micro]m) of the epineurial vessels. Mean arterial pressure was not affected by either acetylcholine (baseline: 103.8 [+ or -] 1.8 mm Hg, acetylcholine: 102.8 [+ or -] 3.2 mm Hg) or atropine (baseline: 104.0 [+ or - ] 1.9 mm Hg, atropine: 105.2 [+ or -] 2.2 mm Hg). These data suggest that muscarinic-receptor-mediated responses can affect the diameter of the epineurial vessels at the sciatic nerve. In addition, muscarinic-receptor-mediated responses appear to contribute to baseline diameter of epineurial vessels at the sciatic nerve. Key words: sciatic nerve, epineurial vasculature, intravital microscopy, muscarinic receptor, acetylcholine, atropine. Dans cette etude, nous avons utilise un modele de rat anesthesie en vue d'observer directement les variations du diametre des vaisseaux alimentant le nerf sciatique en reaction a l'acetylcholine ([10.sup.-4] M), un agoniste des recepteurs muscariniques, et a l'atropine ([10.sup.-5] M), un antagoniste des recepteurs muscariniques. L'application topique d'acetylcholine a entraine une augmentation du diametre des vaisseaux de l'epinerve (depart: 22,0 [+ or -] 2,5 [micro]m, acetylcholine : 28,8 [+ or -] 3,3 [micro]m), tandis que l'application topique d'atropine a entraine leur diminution (depart: 26,6 [+ or -] 3,2 [micro]m, atropine : 15,5 [+ or -] 3,6 [micro]m). La tension arterielle moyenne n'etait pas affectee par l'acetylcholine (depart : 103,8 [+ or -] 1,8 mm Hg, acetylcholine : 102,8 [+ or -] 3,2 mm Hg) ni par l'atropine (depart : 104,0 [+ or -] 1,9 mm Hg, atropine : 105,2 [+ or -] 2,2 mm Hg). Ces donnees laissent entrevoir que des reactions mediees par les recepteurs muscariniques peuvent affecter le diametre des vaisseaux de l'epinerve du nerf sciatique. De plus, des reactions mediees par les recepteurs muscariniques semblent participer a l'etablissement du diametre de depart des vaisseaux de l'epinerve du nerf sciatique. [Traduit par la Redaction] Mots-cles: nerf sciatique, vaisseaux de l'epinerve, microscopie intravitale, recepteur muscarinique, acetylcholine, atropine., Introduction To maintain proper function, the peripheral nerves require sufficient blood flow. Decreases in peripheral nerve blood flow have been associated with decreased nerve conduction velocity, nerve atrophy, and cell [...]

A plasma physics experiment is described, which is suitable for undergraduate courses in electromagnetism as well as for independent projects. Using the plasma of a fluorescent lamp inside a conducting cavity that is immersed in a magnetic field, the experiment shows the effect of electron cyclotron motion of plasma electrons on the resonant modes of the cavity. An added benefit of the magnetic field is the ability to measure the plasma density through a frequency shift technique, but without having to know the mode frequencies in the absence of plasma. Density measurements made using this technique are consistent with those described in an earlier article on the unmagnetized fluorescent lamp plasma, and with the literature on fluorescent lamps and gas discharges. Understanding the experiment described here will give the advanced undergraduate experience in the theory of electromagnetic wave propagation in magnetized plasma, in the theory of resonant cavities, and in microwave and instrumentation techniques.

Background: Collaboratively exploring what matters to people, their understanding of concepts and their ideas for innovation can be a challenge in practice development, research and education due to potential difficulties in articulating complex issues. Visual inquiry is described as a process that involves the use of generic images to facilitate dynamic dialogue between the inquirer and participants, in order to support shared understanding and co-production of knowledge. Aim: The aim was twofold -- first to describe the visual inquiry method and second to explore the experiences of using it in practice development, research and education. Research design: Qualitative data were generated from a group of academics (n=8) who took part in a cooperative inquiry, exploring their experience of using this visual inquiry in 15 independent studies. Findings: The eight academics (inquirers) drew on their experience of using visual inquiry from 15 independent studies. Analysis of the qualitative data identified eight themes in relation to the process and outcomes of using visual inquiry: evocative participation; playfulness; holding vulnerability; welcoming authenticity; illumination; surfacing depth; unearthing possibilities; and evoking surprise and provocation. Conclusion: Visual inquiry was found to be a useful method for opening up dialogue, allowing the facilitator to adopt a flexible approach and the participant to richly articulate insights into their cognitive, emotional and experiential worlds. Implications for practice: • Visual inquiry is a useful method for practitioners looking to open up dialogue and uncover tacit knowledge in practice development, research and education • It is a particularly useful method for those new to facilitation, practice development and research, and encourages an improvisational approach • Cooperative inquiry enables us to gain insight into our own practice and explore possibilities for the future [ABSTRACT FROM AUTHOR]