This thesis contains four manuscripts examining the respiratory mechanics of normal and stuttering speech. The first study (J.Appl.Physiol. 75 (2):696-703, 1993) examined lung volume (V scL) during stutterers' relatively fluent speech. We showed that stutterers used the V scL extremes. This suggested that stutterers recruited their respiratory muscles in a different manner than normals to maintain subglottic pressure (Psg). We therefore investigated respiratory muscle recruitment patterns in normals and stutterers. In the second study, (submitted to J.A.P.), we modified the Campbell pressure volume diagram by the addition of abdominal pressure (Pab) and by the use of a surrogate relaxation curve. The addition of Pab allowed us to differentiate between diaphragmatic and non diaphragmatic inspiratory muscles and to quantify expiratory muscle recruitment. The surrogate curve provided a good approximation of the true relaxation curve (non significant difference between surrogate and true relaxation curves: P $>$.10). The third study (submitted to J.A.P.) used the modified diagram to examine respiratory muscle recruitment patterns, instantaneous Psg, voluntary hyperinflation and intrinsic positive end-expiratory pressures (PEEPi) during normal and stuttering speech. Stutterers used consistent muscle recruitment patterns and consistent V scL but Psg was not as well controlled as in normals. Because a lack of control of Psg could have an immediate effect on the glottis, particularly at high or low V scL, we measured instantaneous Psg and flow in the final study (to be submitted to J.A.P.) to give us instantaneous glottal resistance. In this study we were able to plot a 'family' of glottal resistances that covered normal speech. This provided a normal envelope of resistances. When stutterers were fluent they remained within both the flow and Psg limits set by the normals' envelope. When they were fluent both Psg and flow extended beyond the normals' envelope. We conclude

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Content removed due to copyright restriction: Appendix 6 Cooper, C. V., Stelwagen, K., Singh, K., Farr, V. C., Prosser, C. G., and Davis, S. R. (2004): Expression of the tight junction protein zonula occludens-1 during mammary engorgement. Proceedings of the New Zealand Society of Animal Production 64,43-47. Singh, K., Dobson, J., Phyn, C. V. C., Davis, S. R., Farr, V. C., Molenaar, A. J., and Stelwagen, K. (2005): Milk accumulation decreases expression of genes involved in cell-extracellular matrix communication and is associated with induction of apoptosis in the bovine mammary gland. Livestock Production Science 98,67-78. Appendix 7 McMahon, C.D., Farr, V.C., Singh, K., Wheeler, T.T. and Davis, S.R. (2004). Decreased expression of ß1-integrin and focal adhesion kinase in epithelial cells may initiate involution of mammary glands. Journal of Cellular Physiology 200, 318-325 / Extended periods of milk accumulation result in loss of secretory activity, increased apoptosis and eventually, involution of mammary glands. This process is associated with increased permeability of the tight junction (TJ) complexes between adjacent mammary epithelial cells (MECs). The change in cell shape during mammary engorgement from a cuboidal to a flattened morphology may initiate changes in protein and gene expression (mechanotransduction) that trigger these processes. Therefore, this study examined the regulation of the major TJ protein components during mammary engorgement, and in particular the role of physical distension of the mammary epithelium in the regulatory process. Expression of the integral transmembrane TJ proteins, occludin and claudin-1, and the cytoplasmic TJ protein, ZO-1, were down-regulated in both bovine and rat mammary glands during the early stages of mammary apoptosis and involution following the abrupt cessation of milk removal. In the rat, these responses were locally regulated as they occurred only in teat-sealed glands in a hemi-suckled model. Furthermore, the down-regulation of TJ proteins is consistent with a loss of TJ integrity during mammary engorgement. Induced physical distension of rat mammary glands in vivo transiently up-regulated the expression levels of occludin protein and mRNA, and ZO-1 mRNA, followed by an accelerated decrease in expression compared with the effects of milk accumulation alone. This was associated with the initiation of apoptosis, the up-regulation of the pro-apoptotic factor pSTAT3, and the down-regulation of the cell-ECM survival factor βl-integrin. An in vitro model was also developed to stretch MECs, mimicking the flattening in cell shape during mammary engorgement in vivo. While stretching MECs in vitro did not conclusively alter TJ protein expression, the overall results of this project support further investigation into the role of the TJ complex in mechanotransduction pathways. In addition, the results point to crosstalk between cell-ECM survival signalling and STAT3 death signalling as a candidate for regulation by physical distension of the mammary epithelium. In conclusion, this study supports the hypothesis that physical distension during engorgement of the mammary glands with milk is a primary trigger initiating apoptosis of MECs through changes in the regulation of gene pathways controlling cell survival and death, and the disruption of TJ function.

This thesis documents the annual profiles of the primary reproductive steroids testosterone (T), 17beta-oestradiol (E2) and progesterone (P4), in the reproductive cycles of male and female blue-tongued lizards, Tiliqua nigrolutea. Data collected from a large captive population over three consecutive reproductive seasons are included. Reproductive cycles are discussed in the context of other viviparous squamate reptiles, while a broader comparative approach is used to consider patterns of steroid biosynthesis and peripheral metabolism. The annual patterns of circulating concentrations of T, E2 and P4 have been characterised for both sexes. In males, peak plasma T (10.9 +/- 3.00 ng ml-1) and E2 (778.0 +/- 120.00 pg ml-1) concentrations occur coincident with late spermatogenesis and observations of mating, respectively. Plasma P4 concentrations remain basal (< 1.2 ng ml-1) throughout the annual reproductive cycle. In females, increasing plasma E2 concentrations (275.2 +/- 33.87 pg ml-1 - 715.1 +/- 106.68 pg ml-1) are associated with vitellogenesis and plasma T peaks (6.3 +/- 0.63 ng ml-1) in the mating and peri-ovulatory period. In pregnant females, plasma P4 concentrations are elevated for the first two thirds of gestation, peaking in the second trimester at 12.7 +/- 1.27 ng ml-1 and falling rapidly prior to parturition. Concurrently, plasma P4 concentrations in non-reproductively active adult females remain basal (1 - 2 ng ml-1) throughout the year. There is good circumstantial evidence for a multiennial reproductive cycle in females. Parturition occurs late in the active season, presumably leaving little time for females to store sufficient fat reserves to become vitellogenic in the following spring: reproductive opportunities are effectively missed in at least one year following a reproductive effort. Observed reproductive behaviours, including agonistic male - male interactions, mating, and parturition, are documented. An investigation of gonadal steroid biosynthetic pathways in this viviparous squamate is presented. This compares variation in the relative contributions of the delta-4 and delta-5 steroidogenic pathways according to sex and reproductive condition. The delta-4 pathway predominates in both sexes, aligning this species phylogenetically with other reptiles. However, there are clear differences between sexes and with changing reproductive condition in the patterns of production of pathway intermediates and end-products. Additionally, detection of a possibly novel polar steroid as a major end-product of steroid biosynthesis in both sexes is reported. Peripheral (extragonadal) metabolism of T and E2 in a number of reproductively relevant steroid target tissues is compared at times of year chosen to represent three clearly distinctive reproductive conditions in each sex. There are differences both between sexes, between tissue types and with changing reproductive condition in the relative proportions of steroid conjugates and non-conjugated derivatives produced. Biosynthetic pathway activity and peripheral steroid metabolism both appear to be plastic in response to changing reproductive condition in Tiliqua nigrolutea. With a comprehensive database of information about the reproductive endocrinology and physiology of Tiliqua nigrolutea, this species is now available as a model to further examine selected aspects of the steroid hormone control of reproductive physiology and behaviour in a cool temperate, viviparous reptile.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2003. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2000. / Härtill 4 uppsatser.

Thesis (Ph. D.)--University of Illinois at Urbana-Champaign, 2005. / (UnM)AAI3202116. Adviser: Arthur L. DeVries. Source: Dissertation Abstracts International, Volume: 67-02, Section: B, page: 0633.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2008. / Härtill 5 uppsatser.

abstract: Though it is a widespread adaptation in humans and many other animals, parental care comes in a variety of forms and its subtle physiological costs, benefits, and tradeoffs related to offspring are often unknown. Thus, I studied the hydric, respiratory, thermal, and fitness dynamics of maternal egg-brooding behavior in Children's pythons (Antaresia childreni). I demonstrated that tight coiling detrimentally creates a hypoxic developmental environment that is alleviated by periodic postural adjustments. Alternatively, maternal postural adjustments detrimentally elevate rates of egg water loss relative to tight coiling. Despite ventilating postural adjustments, the developmental environment becomes increasingly hypoxic near the end of incubation, which reduces embryonic metabolism. I further demonstrated that brooding-induced hypoxia detrimentally affects offspring size, performance, locomotion, and behavior. Thus, parental care in A. childreni comes at a cost to offspring due to intra-offspring tradeoffs (i.e., those that reflect competing offspring needs, such as water balance and respiration). Next, I showed that, despite being unable to intrinsically produce body heat, A. childreni adjust egg-brooding behavior in response to shifts in nest temperature, which enhances egg temperature (e.g., reduced tight coiling during nest warming facilitated beneficial heat transfer to eggs). Last, I demonstrated that A. childreni adaptively adjust their egg-brooding behaviors due to an interaction between nest temperature and humidity. Specifically, females' behavioral response to nest warming was eliminated during low nest humidity. In combination with other studies, these results show that female pythons sense environmental temperature and humidity and utilize this information at multiple time points (i.e., during gravidity [egg bearing], at oviposition [egg laying], and during egg brooding) to enhance the developmental environment of their offspring. This research demonstrates that maternal behaviors that are simple and subtle, yet easily quantifiable, can balance several critical developmental variables (i.e., thermoregulation, water balance, and respiration). / Dissertation/Thesis / Ph.D. Biology 2011

Orientador: Augusto Shinya Abe / Coorientador: Cleo Alcantara Costa Leite / Banca: José Eduardo de Carvalho / Banca: Luiz Henrique Florindo / Resumo: Em répteis não crocodilianos, o ventrículo parcialmente dividido permite que o sangue venoso pobre em oxigênio recircule no circuito sistêmico, configurando um desvio sanguíneo intracardíaco ("shunt") da direita para a esquerda (DSIc D-E), ou que o sangue arterial rico em oxigênio retorne ao circuito pulmonar, configurando um desvio sanguíneo intracardíaco da esquerda para a direita (DSIc E-D). Teoricamente, se o DSIc apresentar alguma vantagem adaptativa, seria controlado, ao invés de uma mera consequência passiva do sistema circulatório às mudanças das resistências vasculares. O nervo vago inerva o tronco pulmonar e possui influência no controle da resistência do circuito pulmonar. Assim, o aumento ou diminuição desta resistência poderia definir a direção do desvio sanguíneo resultante. Neste estudo foi postulada a hipótese de que a ausência do tônus vagal causaria mudanças no controle do DSIc em animais submetidos a variações na temperatura e na atividade. Para tanto, foram comparados dois grupos de cascavéis, Crotalus durissus, com nervo vago intacto ou seccionado, submetidas às mesmas condições de temperatura e de atividade. Os parâmetros hemodinâmicos foram aferidos através de canulação oclusiva. De forma geral, o aumento da temperatura e da atividade aumentaram a frequência cardíaca (fH), débito cardíaco (DC), fluxo sanguíneo pulmonar (Qpul) e fluxo sanguíneo sistêmico (Qsis), embora apenas a atividade tenha feito com que as serpentes desenvolvessem um DSIc E-D como resposta ao aumento da demanda de O2 nos tecidos. A atividade também foi responsável pelo aumento das pressões arteriais média sistêmica e pulmonar. A vagotomia unilateral também causa aumento dos fluxos sanguíneos, embora não afete a fH. A ausência do controle vagal tem maior efeito no controle da resistência... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In non crocodilian reptiles, the ventricle is partially divided and allows venous blood, low in oxygen, to recirculate the systemic circuit, which is referred to as a right-to-left shunt (R-L shunt), or the oxygen-rich blood to return to the pulmonary circuit, referred to as a left-to-right shunt (L-R shunt). In theory, if intracardiac shunts provide any adaptive advantage, it would be controlled rather than be a passive consequence of changes in vascular resistances. The vagus nerve innervates the pulmonary trunk and has a role in controlling the resistance of the pulmonary circuit (Rpul). Thus, the control of Rpul could set the direction of the resulting shunt. In this study we hypothesized that the lack of vagal tone causes changes in control of intracardiac shunts in animals subjected to variations in temperature and activity. Therefore, we compared two groups of South American rattlesnakes, Crotalus durissus, with the vagus nerve intact or severed, subjected to the same conditions of temperature and activity. Hemodynamic parameters were measured by occlusive cannulation. Generally, increasing the temperature and the activity increased heart rate (fH), cardiac output (CO), pulmonary blood flow (Qpul) and systemic blood flow (Qsys), although only activity has caused to develop a R-L shunt in response to increased demand for O2 in the tissues. The activity was also responsible for increase in mean systemic and pulmonary arterial pressure. Unilateral vagotomy also increased blood flow, but did not affect fH. The absence of vagal control has more effect in controlling Rpul, causing changes in shunt patterns, especially when the animal was active. Under such condition, the organism seemed to offset the effects on hemodynamic shunt, resulting from changes in systemic resistance, with changes in CO. Thus, CO is elevated until Qpul is at an... (Complete abstract click electronic access below) / Mestre