Unraveling the directional relationship of sleep and migraine-like pain.

Migraine and sleep disorders are common co-morbidities. Patients frequently link their sleep to migraine attacks suggesting a potential causal relationship between these conditions. However, whether migraine pain promotes or disrupts sleep or whether sleep disruption can increase the risk of migraine remains unknown.

Surviving winter on the Qinghai-Tibetan Plateau: Pikas suppress energy demands and exploit yak feces to survive winter.

The Qinghai-Tibetan Plateau, with low precipitation, low oxygen partial pressure, and temperatures routinely dropping below -30 °C in winter, presents several physiological challenges to its fauna. Yet it is home to many endemic mammalian species, including the plateau pika (). How these small animals that are incapable of hibernation survive the winter is an enigma.

Determining seabird body condition using nonlethal measures.

Energy stores are critical for successful breeding, and longitudinal studies require nonlethal methods to measure energy stores ("body condition"). Nonlethal techniques for measuring energy reserves are seldom verified independently. We compare body mass, size-corrected mass (SCM), plasma lipids, and isotopic dilution with extracted total body lipid content in three seabird species (thick-billed murres Uria lomvia, all four measures; northern fulmars Fulmarus glacialis, three measures; and black-legged kittiwakes Rissa tridactyla, two measures).

Energy expenditure and water turnover in hunting dogs in winter conditions.

Hunting with dogs in winter conditions is practised in the Nordic countries. The present study aimed at determining daily energy expenditure (DEE) and body water turnover (BWT) by the doubly labelled water technique in eight hunting dogs (body-weight (BW) range 14-27 kg) working 3 h/d for 3 d (-6 °C) on ground covered with 20-40 cm of loose snow, to provide information on energy and water requirements. The mean distance run during the hunting period was recorded by the global positioning system and averaged 19.

Energy metabolism of Inuit sled dogs.

We explored how seasonal changes in temperature, exercise and food supply affected energy metabolism and heart rate of Inuit dogs in Greenland. Using open flow respirometry, doubly labeled water, and heart rate recording, we measured metabolic rates of the same dogs at two different locations: at one location the dogs were fed with high energy food throughout the year while at the other location they were fed with low energy food during summer. Our key questions were: is resting metabolic rate (RMR) increased during the winter season when dogs are working? Does feeding regime affect RMR during summer? What is the proportion of metabolic rate (MR) devoted to specific dynamic action (SDA), and what is the metabolic scope of working Inuit sled dogs? The Inuit dogs had an extremely wide thermoneutral zone extending down to -25 degrees C.

Lifelong alpha-tocopherol supplementation increases the median life span of C57BL/6 mice in the cold but has only minor effects on oxidative damage.

The effects of dietary antioxidant supplementation on oxidative stress and life span are confused. We maintained C57BL/6 mice at 7 +/- 2 degrees C and supplemented their diet with alpha-tocopherol from 4 months of age. Supplementation significantly increased (p = 0.

Life-long vitamin C supplementation in combination with cold exposure does not affect oxidative damage or lifespan in mice, but decreases expression of antioxidant protection genes.

Oxidative stress is suggested to be central to the ageing process, with endogenous antioxidant defence and repair mechanisms in place to minimize damage. Theoretically, supplementation with exogenous antioxidants might support the endogenous antioxidant system, thereby reducing oxidative damage, ageing-related functional decline and prolonging life- and health-span. Yet supplementation trials with antioxidants in animal models have had minimal success.

Uncoupled and surviving: individual mice with high metabolism have greater mitochondrial uncoupling and live longer.

Two theories of how energy metabolism should be associated with longevity, both mediated via free-radical production, make completely contrary predictions. The 'rate of living-free-radical theory' (Pearl, 1928; Harman, 1956; Sohal, 2002) suggests a negative association, the 'uncoupling to survive' hypothesis (Brand, 2000) suggests the correlation should be positive. Existing empirical data on this issue is contradictory and extremely confused (Rubner, 1908; Yan & Sohal, 2000; Ragland & Sohal, 1975; Daan et al.