What's bred in bone: effects of thyroid hormone supplementation on bone growth and remodelling in ectotherms and endotherms. Influence of resting metabolic rate (RMR) and exercise activity on bone microstructure is investigated in a variety of amniote taxa. By varying the dose of supplemental triiodothyronine (T3), ectotherms are made hyperthyroid with elevated RMR, and endotherms - hypothyroid with depressed RMR. Effects of T3 are compared against those of mechanical loading, in form of increa ....What's bred in bone: effects of thyroid hormone supplementation on bone growth and remodelling in ectotherms and endotherms. Influence of resting metabolic rate (RMR) and exercise activity on bone microstructure is investigated in a variety of amniote taxa. By varying the dose of supplemental triiodothyronine (T3), ectotherms are made hyperthyroid with elevated RMR, and endotherms - hypothyroid with depressed RMR. Effects of T3 are compared against those of mechanical loading, in form of increased daily treadmill exercise. Rates of bone growth and secondary remodelling are determined by histological analysis, and correlated with T3 and bone strain levels. The study tests the hypothesis that evolution of endothermy can be inferred from bone microstructure of fossil bones.Read moreRead less
Assessment of bentonites as remediating agents for metal contaminated soils using innovative bioavailability reduction technology. The project seeks to carry out research on innovative, economically sustainable risk-based solutions (soil amendments) for metal-contaminated soils and methods for assessing the potential risk/bioavailability of soil bound metals. The work will determine factors affecting the reactivity, mobility and bioavailability of metals in Australian soils and clays and method ....Assessment of bentonites as remediating agents for metal contaminated soils using innovative bioavailability reduction technology. The project seeks to carry out research on innovative, economically sustainable risk-based solutions (soil amendments) for metal-contaminated soils and methods for assessing the potential risk/bioavailability of soil bound metals. The work will determine factors affecting the reactivity, mobility and bioavailability of metals in Australian soils and clays and methods by which these can be controlled. Remediation options, such as natural clay amendments to reduce metal bioavailability, will be assessed against in vivo and in vitro bioavailability assays in order to develop cost effective, risk-based remediation strategies and assessment protocols for urban and rural contaminated soils.Read moreRead less
Insights into macroevolution using a model adaptive radiation of lizards (Lerista). Australia has arguably the greatest diversity of lizards in the world. This research will investigate how this diversity arose, using Lerista, a radiation of skinks with over 80 species spanning fully limbed to totally legless forms. We will investigate how development, geographic distribution and morphological features have influenced the evolutionary diversification of Lerista. We will also map the biodivers ....Insights into macroevolution using a model adaptive radiation of lizards (Lerista). Australia has arguably the greatest diversity of lizards in the world. This research will investigate how this diversity arose, using Lerista, a radiation of skinks with over 80 species spanning fully limbed to totally legless forms. We will investigate how development, geographic distribution and morphological features have influenced the evolutionary diversification of Lerista. We will also map the biodiversity of Lerista across Australia using (and thus testing) several alternative methods of quantifying biodiversity. Such knowledge is important as many hotspots of Lerista diversity are coming under increasing human pressure (e.g. mid-coast of WA), and many species have very localised ranges.Read moreRead less
The Role Of Arousal And Diaphragm Displacement In The Pathogenesis Of Obstructive Sleep Apnoea
Funder
National Health and Medical Research Council
Funding Amount
$410,875.00
Summary
Obstructive sleep apnea (OSA) affects 4% of men and causes excessive daytime sleepiness leading to increased accidents, high blood pressure and premature cardiovascular disease e.g. heart attacks and strokes. OSA is characterized by repetitive obstructions of the floppy portion of the throat during sleep with adverse effects on oxygen levels and sleep quality. OSA is strongly associated with obesity and is 2-3 times more common in men than women. How obesity and male gender predispose to OSA is ....Obstructive sleep apnea (OSA) affects 4% of men and causes excessive daytime sleepiness leading to increased accidents, high blood pressure and premature cardiovascular disease e.g. heart attacks and strokes. OSA is characterized by repetitive obstructions of the floppy portion of the throat during sleep with adverse effects on oxygen levels and sleep quality. OSA is strongly associated with obesity and is 2-3 times more common in men than women. How obesity and male gender predispose to OSA is not known. We will investigate two factors that we believe are most likely involved in causing and explaining this gender difference in OSA. We will examine if breathing responses with brief awakening are sufficient to promote OSA patterns of breathing in snorers and if they are greater in male than female OSA patients. We have already shown that healthy men have greater breathing response to arousal compared to women. These brief arousals occur hundreds of times a night in OSA patients, and over-breathing on arousal may increase the probability of upper airway obstruction on falling back to sleep. We will also investigate why even healthy men show greater breathing responses compared to women. Men tend to accumulate fat centrally, particularly in the abdomen, whereas in women fat tends to be distributed more to the hips and thighs. This could be very important in OSA because downward pull exerted on the upper airway by the diaphragm is likely to be reduced in people with more abdominal obesity. This mechanisms has not yet been studied in humans. We will therefore investigate if increased forces placed on the diaphragm during sleep make the upper airway more prone to collapse. We will also investigate these effects during sleep onset, when there may well be important changes in diaphragm position as muscles relax.Read moreRead less