Ian Macdonald

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Flavanols are the main flavonoids found in cocoa and chocolate, and can be especially abundant in certain cocoas. Research over the past decade has identified flavanols as showing diverse beneficial physiologic and antioxidant effects, particularly in context of vascular function. The present study employed functional magnetic resonance imaging based on(More)
This study investigated the effect of carbohydrate (CHO) ingestion on skeletal muscle creatine (Cr) accumulation during Cr supplementation in humans. Muscle biopsy, urine, and plasma samples were obtained from 24 males before and after ingesting 5 g Cr in solution (group A) or 5 g Cr followed, 30 min later, by 93 g simple CHO in solution (group B) four(More)
A large metabolomics study was performed on 600 plasma samples taken at four time points before and after a single intake of a high fat test meal by obese and lean subjects. All samples were analyzed by a liquid chromatography-mass spectrometry (LC-MS) lipidomic method for metabolic profiling. A pragmatic approach combining several well-established(More)
The Cape Peninsula, a 470 km2 area of rugged scenery and varied climate, is located at the southwestern tip of the Cape Floristic Region, South Africa. The Peninsula is home to 2285 plant species and is a globally important hot-spot of biodiversity for higher plants and invertebrates. This paper provides a broad overview of the physiography, biological(More)
Conventional functional imaging paradigms use periods of repetitive task performance to generate sustained functional signal changes. We have developed a technique of imaging the small, transient signal changes that occur after single cognitive events. The technique uses echo-planar imaging at 3 T to generate functional images of the whole brain with a(More)
Hypoglycaemia without warning is a dangerous complication of insulin-dependent diabetes mellitus and it limits the use of intensified insulin therapy to reduce chronic diabetic complications. To investigate the possibility of restoring awareness; symptomatic, cognitive, and hormonal responses to controlled hypoglycaemia were studied in insulin-dependent(More)
OBJECTIVE To investigate the impact of a high-sucrose diet vs a high-starch and a high-fat diet on 14 d ad libitum energy intake, body weight, energy expenditure and sympathoadrenal activity. MEASUREMENTS Food intake; body weight and composition (bioelectrical impedance); 24 h energy expenditure, substrate oxidation rates, spontaneous physical activity,(More)
Two men, R.F. and M.S., pulled sledges each with starting masses of 222 kg, 2300 km across Antarctica. Exercise was performed for approximately 10 h each day for 95 days. Despite an average energy intake of 21.3 MJ · day−1 both subjects lost more than 25% of body weight. Energy expenditure was measured using energy balance data (EB) and isotope-labelled(More)
Blood and urine samples were obtained from four groups of healthy male subjects (A-D, total n = 22) before, during and after ingesting the following: group A, 5 g of creatine in solution; groups B and C, 5 g of creatine and 93 g of simple carbohydrate in solution: group D, a creatine- and carbohydrate-free solution. Subjects ingested the above preparations(More)