Extremely short duration high intensity interval training substantially improves insulin action in young healthy males

Background: Traditional high volume aerobic exercise training reduces cardiovascular and metabolic disease risk but involves a substantial time commitment. Extremely low volume high-intensity interval training (HIT) has recently been demonstrated to produce improvements to aerobic function, but it is unknown whether HIT has the capacity to improve insulin action and hence glycemic control. Methods: Sixteen young men (age: 21 ± 2 y; BMI: 23.7 ± 3.1 kg·m-2; VO2peak: 48 ± 9 ml·kg-1·min-1) performed 2 weeks of supervised HIT comprising of a total of 15 min of exercise (6 sessions; 4-6 × 30-s cycle sprints per session). Aerobic performance (250-kJ self-paced cycling time trial), and glucose, insulin and NEFA responses to a 75-g oral glucose load (oral glucose tolerance test; OGTT) were determined before and after training. Results: Following 2 weeks of HIT, the area under the plasma glucose, insulin and NEFA concentration-time curves were all reduced (12%, 37%, 26% respectively, all P < 0.001). Fasting plasma insulin and glucose concentrations remained unchanged, but there was a tendency for reduced fasting plasma NEFA concentrations post-training (pre: 350 ± 36 v post: 290 ± 39 μmol·l-1, P = 0.058). Insulin sensitivity, as measured by the Cederholm index, was improved by 23% (P < 0.01), while aerobic cycling performance improved by ∼6% (P < 0.01). Conclusion: The efficacy of a high intensity exercise protocol, involving only ∼250 kcal of work each week, to substantially improve insulin action in young sedentary subjects is remarkable. This novel time-efficient training paradigm can be used as a strategy to reduce metabolic risk factors in young and middle aged sedentary populations who otherwise would not adhere to time consuming traditional aerobic exercise regimes

Optogenetic Applications in Retinal Glia and Neurons

Optogenetics, the ability to control cells with light, has revolutionized neuroscience by endowing researchers with hyper precise tools which can dissect neural circuits. However, the use of optogenetic effectors is not limited to academic studies on neurons. This dissertation examines two alternative applications of optogenetics: to study glia-neuron interactions and to therapeutically restore light sensitivity to degenerate retinas. In order express these optogenetic effectors, Adeno-Associated Virus (AAV) was used to deliver transgenes. Over the course of these studies, the ability to specifically target certain types of cells became paramount. Specifically, special AAV capsid variants had to be used in order to transduce Müller glia, the principal glia cell of the retina. The capsid variants, 7m8 and ShH10, are not specific for Müller cells, so different glial promoters were investigated. Two promoters evaluated, GLAST and gfaABC1D, had unexpected expression profiles. Although GLAST is a Müller cell specific protein, the GLAST promoter was unable to restrict transgene expression to Müller glia. However, the smaller the gfaABC1D promoter was able to completely restrict transgene expression to retinal glia in both health and disease.With new methods to selectively transduce Müller glia, their role in glutamate uptake was investigated. The electrogenic transporters used to transport glutamate against its concentration gradient require a hyperpolarized membrane potential made possible through high expression of potassium channels. If glutamate uptake was dependent on Müller cell membrane potential, then transient depolarization of the Müller glia should inhibit glutamate uptake. To transiently depolarize Müller cells, they were targeted to express a bistable channelrhodopsin2 (ChR2) mutant (C128S/D156A, “BiChR2”). The effect of BiChR2 induced Müller glia depolarization on the retinal light response was investigated by examining the electroretinogram (ERG). While there were no significant changes to the ON-bipolar cell generated ERG B-wave, subtle temporal changes in arose that should be investigated further. Optogenetics have a therapeutic potential to restore vision in degenerate retinas. People with late stage retinal degenerative disease lose sight as a consequence of photoreceptor death. However, other retinal cells remain. Endowing the surviving retinal cells with the ability to sense light through optogenetics could restore sight. The effectiveness of optogenetics tools used for vision restoration were analyzed based on their light and temporal sensitivity

Optogenetic Applications in Retinal Glia and Neurons

Optogenetics, the ability to control cells with light, has revolutionized neuroscience by endowing researchers with hyper precise tools which can dissect neural circuits. However, the use of optogenetic effectors is not limited to academic studies on neurons. This dissertation examines two alternative applications of optogenetics: to study glia-neuron interactions and to therapeutically restore light sensitivity to degenerate retinas. In order express these optogenetic effectors, Adeno-Associated Virus (AAV) was used to deliver transgenes. Over the course of these studies, the ability to specifically target certain types of cells became paramount. Specifically, special AAV capsid variants had to be used in order to transduce Müller glia, the principal glia cell of the retina. The capsid variants, 7m8 and ShH10, are not specific for Müller cells, so different glial promoters were investigated. Two promoters evaluated, GLAST and gfaABC1D, had unexpected expression profiles. Although GLAST is a Müller cell specific protein, the GLAST promoter was unable to restrict transgene expression to Müller glia. However, the smaller the gfaABC1D promoter was able to completely restrict transgene expression to retinal glia in both health and disease.With new methods to selectively transduce Müller glia, their role in glutamate uptake was investigated. The electrogenic transporters used to transport glutamate against its concentration gradient require a hyperpolarized membrane potential made possible through high expression of potassium channels. If glutamate uptake was dependent on Müller cell membrane potential, then transient depolarization of the Müller glia should inhibit glutamate uptake. To transiently depolarize Müller cells, they were targeted to express a bistable channelrhodopsin2 (ChR2) mutant (C128S/D156A, “BiChR2”). The effect of BiChR2 induced Müller glia depolarization on the retinal light response was investigated by examining the electroretinogram (ERG). While there were no significant changes to the ON-bipolar cell generated ERG B-wave, subtle temporal changes in arose that should be investigated further. Optogenetics have a therapeutic potential to restore vision in degenerate retinas. People with late stage retinal degenerative disease lose sight as a consequence of photoreceptor death. However, other retinal cells remain. Endowing the surviving retinal cells with the ability to sense light through optogenetics could restore sight. The effectiveness of optogenetics tools used for vision restoration were analyzed based on their light and temporal sensitivity

Spontaneous Volunteering During Natural Disasters

The recent spate of natural disasters across Australia has led to an outpouring of spontaneous volunteering, both formally through nonprofit and government agencies and informally through local community and online networks. Relatively little is understood about the motivations and characteristics of spontaneous volunteers. The aims of this project were to: Examine the characteristics and motivations of spontaneous volunteers who respond to a crisis event; Illuminate the effects of spontaneous volunteering on personal, social and civic networks; Explicate the conditions under which sustained volunteering and other forms of civic engagement arise from spontaneous volunteering and; Consider the practical implications of these findings for organisations involved in coordinating volunteers both with and beyond disaster events

Spontaneous volunteering: trends and challenges in the Australian context

This chapter reviews spontaneous volunteering in Australia and its challenges for volunteers and volunteer organisations. Drawing on their own empirical research mzd the wider literature, the authors suggest that better understanding of the nature and functions of spontaneous volunteering is needed to support community resilience and individual wellbeing

Spontaneous volunteering: trends and challenges in the Australian context / Melanie Oppenheimer and Jeni Warburton (eds.)

Abstract not available

Culturally diverse collaborations: a focus on communication and shared understanding

This paper explores communication and shared understanding in culturally diverse collaborations. It draws on empirical research involving a large UK organization that collaborates with many public, private and not-for-profit organizations located in many different countries across Africa, Asia, Europe and the USA. Through analysis located in a ‘culture paradox’, it proposes a multifaceted account of cultural diversity which has implications for how communication and shared understanding in culturally diverse collaborations may be understood and managed. It develops two specific management tensions pertaining to ‘developing cultural sensitivity’ and ‘designing communication processes’. These tensions explicate the complexity of culturally diverse contexts and highlight pertinent trade-offs and compromises that may enhance a collaboration’s ability to yield advantage rather than inertia

Engineered AAVs for non-invasive gene delivery to rodent and non-human primate nervous systems

Gene therapy offers great promise in addressing neuropathologies associated with the central and peripheral nervous systems (CNS and PNS). However, genetic access remains difficult, reflecting the critical need for the development of effective and non-invasive gene delivery vectors across species. To that end, we evolved adeno-associated virus serotype 9 (AAV9) capsid in mice and validated two capsids, AAV-MaCPNS1 and AAV-MaCPNS2, across rodent species (mice and rats) and non-human primate (NHP) species (marmosets and rhesus macaques). Intravenous administration of either AAV efficiently transduced the PNS in rodents and both the PNS and CNS in NHPs. Furthermore, we used AAV-MaCPNS1 in mice to systemically deliver the following: (1) the neuronal sensor jGCaMP8s to record calcium signal dynamics in nodose ganglia and (2) the neuronal actuator DREADD to dorsal root ganglia to mediate pain. This conclusively demonstrates the translatability of these two systemic AAVs across four species and their functional utility through proof-of-concept studies in mice