Andrew Murray

The life of a philosopher is foremost the life of thinking but it is also the life of imagination that dreams of and investigates possibilities that might not otherwise have been raised. The life of a Christian is the life of Faith, Hope and Charity, and so it both looks to things beyond this world and regards this world with compassion. The two can work together. Faith softens reason, and reason sharpens Faith. Imagination finds new ways to articulate in concrete circumstances what has belonged to long traditions of thought. These essays cover a wide range of topics either by way of simple reflection on life or in response to issues that arose around the time of their writing. The period of their writing was a varied one. Life looked so stable in the mid-nine-ties that we contemplated Australia becoming a republic and sought Aboriginal reconciliation. It remained uncomplicated at the time of the Olympic Games in 2000 but became troubled by political events and by the terrorist attacks of 2001. The essays respond to the issues of this time. Four essays not published in the Weekly have been added to take note of more recent changes that have taken place in the Church and in our world.

At extreme altitude (>5,000 – 5,500 m), sustained hypoxia threatens human function and survival, and is associated with marked involuntary weight loss (cachexia). This seems to be a coordinated response: appetite and protein synthesis are suppressed, and muscle catabolism promoted. We hypothesise that, rather than simply being pathophysiological dysregulation, this cachexia is protective. Ketone bodies, synthesised during relative starvation, protect tissues such as the brain from reduced oxygen availability by mechanisms including the reduced generation of reactive oxygen species, improved mitochondrial efficiency and activation of the ATP‐sensitive potassium (KATP) channel. Amino acids released from skeletal muscle also protect cells from hypoxia, and may interact synergistically with ketones to offer added protection. We thus propose that weight loss in hypoxia is an adaptive response: the amino acids and ketone bodies made available act not only as metabolic substrates, but as metabolic modulators, protecting cells from the hypoxic challenge.Also watch the Video Abstract.