Psychological aspects of the longest, solo, unsupported one-way polar ski expedition in Antarctica by a female adventurer.

INTRODUCTION: Antarctic expeditions present exceptional physiological and mental challenges. Research data are lacking on psychological aspects of such endeavours. The aim of our study is to provide data on changes in mood, well-being, personality traits and personal experiences during an Antarctica crossing. METHODS: This is a study of a 33-year-old female British Army officer (height 175 cm; weight 75 kg; body mass index 24.49 kg/m2; VO2max 49 mL/kg/min) who completed the longest, solo, unsupported, one-way polar ski expedition. The expedition started at Hercules Inlet and finished at Ross Ice Shelf, lasting 70 days and 16 hours covering 1484.53 km, with temperatures estimating from -12°C to -50°C and wind speeds of up to 60 miles per hour. The adventurer pulled all equipment and nutrition in a pulk (sled), weighing approximately 120 kg. Five psychometric questionnaires were completed pre post and during the expedition, including the International Personality Item Pool - Neuroticism, Extraversion and Openness-60, Brief Assessment of Mood, Positive and Negative Affective Schedule, Profile of Mood States, Wellness questionnaire, as well as an unstructured open questionnaire. RESULTS: Mood generally deteriorated, particularly positive affective mood. Scores for fatigue and muscle soreness increased, with a reduction in sleep times. Personality traits of openness, agreeableness, and conscientiousness remained stable throughout the expedition, with some reduction in extraversion and an increase in neuroticism. Personal accounts give a unique insight into the increasing demands on the mental and physical impact of the expedition. CONCLUSIONS: Meticulous preparation and planning may have led to a successful expedition, including physical preparation, prior on-field experience, and psychological preparedness and resiliance. Some of these strategies may be applicable to a range of settings, including future Antarctic expeditions, expeditions in extreme environments, or missions within a military context.

Temporal and spatial dispersion of human body temperature during deep hypothermia.

BACKGROUND: Clinical temperature management remains challenging. Choosing the right sensor location to determine the core body temperature is a particular matter of academic and clinical debate. This study aimed to investigate the relationship of measured temperatures at different sites during surgery in deep hypothermic patients. METHODS: In this prospective single-centre study, we studied 24 patients undergoing cardiothoracic surgery: 12 in normothermia, 3 in mild, and 9 in deep hypothermia. Temperature recordings of a non-invasive heat flux sensor at the forehead were compared with the arterial outlet temperature of a heart-lung machine, with the temperature on a conventional vesical bladder thermistor and, for patients undergoing deep hypothermia, with oesophageal temperature. RESULTS: Using a linear model for sensor comparison, the arterial outlet sensor showed a difference among the other sensor positions between -0.54 and -1.12°C. The 95% confidence interval ranged between 7.06 and 8.82°C for the upper limit and -8.14 and -10.62°C for the lower limit. Because of the hysteretic shape, the curves were divided into phases and fitted into a non-linear model according to time and placement of the sensors. During cooling and warming phases, a quadratic relationship could be observed among arterial, oesophageal, vesical, and cranial temperature recordings, with coefficients of determination ranging between 0.95 and 0.98 (standard errors of the estimate 0.69-1.12°C). CONCLUSION: We suggest that measured surrogate temperatures as indices of the cerebral temperature (e.g. vesical bladder temperature) should be interpreted with respect to the temporal and spatial dispersion during cooling and rewarming phases.

The Double Sensor-A non-invasive device to continuously monitor core temperature in humans on earth and in space.

The objective of our study was to establish whether rectal temperature recordings in humans could be replaced by a non-invasive skin temperature sensor combined with a heat flux sensor (Double Sensor) located at the forehead to monitor core body temperature changes due to circadian rhythms. Rectal and Double Sensor data were collected continuously for 24h in seven men undertaking strict head-down tilt bed-rest. Individual differences between the two techniques varied between -0.72 and +0.55 degrees C. Nonetheless, when temperature data were approximated by cosinor analysis in order to compare circadian rhythm profiles between methods, it was observed that there were no significant differences between mesor, amplitude, and acrophase (P>0.310). It was therefore concluded that the Double Sensor technology is presently not accurate enough for performing single individual core body temperature measurements under resting conditions at normal ambient room temperature. Yet, it seems to be a valid, non-invasive alternative for monitoring circadian rhythm profiles.

Erythropoietin regulations in humans under different environmental and experimental conditions.

In the adult human, the kidney is the main organ for the production and release of erythropoietin (EPO). EPO is stimulating erythropoiesis by increasing the proliferation, differentiation and maturation of the erythroid precursors. In the last decades, enormous efforts were made in the purification, molecular encoding and description of the EPO gene. This led to an incredible increase in the understanding of the EPO-feedback-regulation loop at a molecular level, especially the oxygen-dependent EPO gene expression, a key function in the regulation loop. However, studies in humans at a systemic level are still very scanty. Therefore, it is the purpose of the present review to report on the main recent investigations on EPO production and release in humans under different environmental and experimental conditions, including: (i) studies on EPO circadian, monthly and even annual variations, (ii) studies in connection with short-, medium- and long-term exercise at sea-level which will be followed (iii) by studies performed at moderate and high altitude.