Thesis (M Nursing)--Montana State University--Bozeman, 2010. / Typescript. Chairperson, Graduate Committee: Elizabeth S. Kinion. Includes bibliographical references (leaves 50-58).

Thesis (M.S.)--Missouri University of Science and Technology, 2010. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed July, 19, 2010) Includes bibliographical references (p. 53-56).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1968. / Typescript. Vita. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1971. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Chicago, 1919. / Caption title. Reprinted from the American journal of physiology, Vol. 49, No. 4, September, 1919. Includes bibliographical references (p. 522).

Thesis--Catholic University of America. / "Paper no. 543. Reprinted from Growth, vol. XXII, pp. 125-166." Bibliography: p. 165-166.

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

1. The role of the catecholamine noradrenaline (NA) was examined during fictive swimming in Xenopus laevis tadpoles. 2. The primary effects of the amine in both embryonic and larval Xenopus was to markedly decrease motor frequency whilst simultaneously reducing rostrocaudal delays during swimming. 3. The NA-mediated modulation of swimming activity in Xenopus larvae can be reversed with phentolamine, a non-selective an adrenergic receptor antagonist, suggesting that NA may be acting through either ?1 or ?2 receptors, or a combination of both. 4. Intracellular recordings made from embryo spinal motorneurones revealed that reciprocal inhibitory glycinergic potentials are enhanced by NA. This effect is most prominent in caudal regions of the spinal cord where inhibitory synaptic drive is generally weaker. 5. NA was also found to enhance glycinergic reciprocal inhibition during swimming in larval spinal cord motomeurones. 6. Intracellular recordings, under tetrodotoxin, reveal that NA enhances the occurrence of spontaneous glycinergic inhibitory post synaptic potentials arising from the terminals of inhibitory intemeurones, suggesting that the amine is acting presynaptically to enhance evoked release of glycine during swimming. 7. The effects of NA on swimming frequency and rostrocaudal delay appear to be largely mediated through an enhancement of glycinergic reciprocal inhibition as blockade of glycine receptors with strychnine weakens the ability of the amine affect these parameters of motor output. 8. The effects of NA on motor output were also examined in embryos of the amphibian Rana temporaria. Whilst NA did not obviously affect swimming activity, the amine induced a non-rhythmic pattern of motor activity. 9. The free radical gas, nitric oxide also induced a non-rhythmic pattern of motor discharge that was remarkably similar to that elicited by NA, indicating that this neural messenger may be important for motor control.

No description available.

This thesis investigates the role of male vocalizations in two aspects of Pacific Tree Frog breeding behavior: Spacing out of males on breeding areas and selection of mates by females. Spacing out: An analysis of nearest neighbor distances of calling frogs showed that males space out more than if distributed randomly on the available calling sites. An addition experiment provided corroborative evidence that males tend not to call too close together; of equal numbers of frogs added to an empty (control) enclosure and an enclosure occupied by calling frogs, more subsequently called in the control. The species' "mating" call (D call), as well as attracting females, functions in spacing out; in an addition experiment, fewer frogs called in an enclosure occupied only by loudspeakers playing back D calls than in the control. Another vocalization (S call) seems to function only in spacing out. If two calling frogs come close together (less than ca. 50 cm), both usually begin making the S call. One frog may then move away; if not, physical combat may follow. I hypothesized that the S call is a stronger warning to nearby males than the D call. A playback experiment partially supported this hypothesis. I consider possible functions of spacing out, and suggest that males which maintain spacing may attract more females than they would otherwise, perhaps because females can more easily locate them. Mate selection: I attempted to test two hypotheses: First, females select large males on the basis of their low-pitched vocalizations (there is an inverse correlation between call pitch and body length). A comparison of body lengths and call pitches of males found in amplexus with a sample of males from the calling population did not support this hypothesis. Second, females choose males which initiate bouts of calling (chorus leaders). Both systematic field observations and a laboratory experiment support this hypothesis. Chorus leaders also end choruses, call at a faster rate during choruses, call more during periods not defined as choruses, and call louder than other frogs. In nature, females may also use these differences as cues in mate selection. The advantages of being a chorus leader should select for frogs calling all of the time, yet frogs show frequent lulls in calling. A playback experiment showed that frogs are less responsive (measured by latency to call) to stimulus calls shortly after having stopped calling than later in the lull period. I hypothesized that fatigue is responsible for this short-term waning of calling tendency. A respirometry experiment suggested (but quite inconclusively) that the fatigue hypothesis is feasible. / Science, Faculty of / Zoology, Department of / Graduate