Weight loss is a well-known phenomenon at high altitude. It is not clear whether the negative energy balance is due to anorexia only or an increased energy expenditure as well. The objective of this study was to gain insight into this matter by measuring simultaneously energy intake, energy expenditure, and body composition during an expedition to Mt. Everest. Subjects were two women and three men between 31 and 42 yr of age. Two subjects were observed during preparation at high altitude, including a 4-day stay in the Alps (4,260 m), and subsequently during four daytime stays in a hypobaric chamber (5,600-7,000 m). Observations at high altitude on Mt. Everest covered a 7- to 10-day interval just before the summit was reached in three subjects and included the summit (8,872 m) in a fourth. Energy intake (EI) was measured with a dietary record, average daily metabolic rate (ADMR) with doubly labeled water, and resting metabolic rate (RMR) with respiratory gas analysis. Body composition was measured before and after the interval from body mass, skinfold thickness, and total body water. Subjects were in negative energy balance (-5.7 +/- 1.9 MJ/day) in both situations, during the preparation in the Alps and on Mt. Everest. The loss of fat mass over the observation intervals was 1.4 +/- 0.7 kg, on average two-thirds of the weight loss (2.2 +/- 1.5 kg), and was significantly correlated with the energy deficit (r = 0.84, P < 0.05). EI on Mt. Everest was 9-13% lower than during the preparation in the Alps.(ABSTRACT TRUNCATED AT 250 WORDS)

In previous studies the doubly labeled water method for measuring energy expenditure in free-living humans has been validated against respirometry under sedentary conditions. In the present investigation, energy expenditure is measured simultaneously with doubly labeled water and respirometry at low- and high-activity levels. Over 6 days, five subjects were measured doing mainly sedentary activities like desk work; their average daily metabolic rate was 1.40 +/- 0.09 (SD) times sleeping metabolic rate. Four subjects were measured twice over 3.5 days, including 2 days with heavy bicycle ergometer work, resulting in an average daily metabolic rate of 2.61 +/- 0.25 (SD) times sleeping metabolic rate. At the low-activity level, energy expenditures from the doubly labeled water method were on the average 1.4 +/- 3.9% (SD) larger than those from respirometry. At the high-activity level, the doubly labeled water method yielded values that were 1.0 +/- 7.0% (SD) lower than those from respirometry. Results demonstrate the utility of the doubly labeled water method for the determination of energy expenditure in the range of activity levels in daily life.

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The provision of lifelong learning facilities is considered to be a major new direction for higher and distance teaching educational institutes catering for the demands of industry and society. ICT networks will in future support seamless, ubiquitous access to lifelong learning facilities at home, at work, in schools and universities. This implies the development of new ways of organizing learning delivery that that goes beyond course and programmecentric models. It envisions a learner-centred, learner-controlled model of distributed lifelong learning. We present a conceptual model for the support of lifelong learning which is based on notions from self-organization theory, learning communities, agent technologies and learning technology specifications such as IMS Learning Design. An exploratory implementation has been developed and used in practice. We reflect on the findings and future directions. 2 Lifelong Learning NetworksBoth higher and distance education are currently exploring the new possibilities offered by eLearning. Today we find new, collaborative initiatives such as virtual universities, consortia and digital universities, which aspire to share learning resources, increase the quantity and quality of educational services, and explore new markets, particularly in the field of lifelong learning (Brookfield, 1987;Cross-Durrant, 1987;Jarvis, 1987;Smith, 1996Smith, , 2001.The underlying idea is that 'lifelong learning' will ultimately provide a major service catering for the needs and demands of industry and society as a whole (Tuijnman, 1992;Ragget, 1996;Schuetze, 2000). Lifelong learning is the concept that refers to the activities a person performs throughout their life to improve their knowledge, skills and competence in a particular field, given some personal, societal or employment related motives (Aspin & Chapman, 2000;Field, 2001;Griffin, 1999).To achieve these aims, educational institutions must offer facilities that meet the needs of learners at various levels of competence throughout their lives. People must be able to use lifelong learning facilities to upgrade their knowledge, skills and competence in a discipline as required. They can also contribute to the facilities by sharing knowledge and supporting other learners. Lifelong learners are not merely consumers of learning facilities, but can be asked to actively contribute to the facilities themselves (Fischer & Ostwald, 2002).A promising approach to lifelong learning is to use ICT networks to connect distributed learners and providers in a discipline to establish Learning Networks (LNs). ICT networks can support seamless, ubiquitous access to learning facilities at work, at home and in schools and universities. Learning resources from providers such as schools, companies, libraries and the learners themselves can be made available from a single point of access and learners can be helped to perform certain tasks more efficiently by including software support.The use of ICT networks implies the development of new ways of organizing...

We investigate incentive mechanisms to increase active participation in Learning Networks.The Learning Network under study is LN4LD, a Learning Network for the exchange of information about the IMS Learning Design specification. We examine how to encourage learners in LN4LD to contribute their knowledge, and whether incentive mechanisms can increase the level of active participation. We describe an incentive mechanism based on constructivist principles and Social Exchange Theory, and experimentation using the mechanism designed to increase the level of active participation. The incentive mechanism allows individual learners to gain personal access to additional information through the accumulation of points earned by making contributions. Repeated measurements according to a simple interrupted time series with removal design show that the level of participation was indeed increased by the introduction of the reward system. It can therefore be considered worthwhile to use incentive mechanisms in Learning Networks. Encouraging participation 4Informed participation for community-based learning and design In addition to improvements in the quality of the learning process, the mutual exchange of information by large numbers of individual learners offers some hope of a solution to the

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Tutors have only limited time to support students. In this paper, we discuss a model that addresses the question of how to help students answer content-related questions. A small group of students is created, which consists of the student who asked the question and peers who should be able to answer it. Criteria used to compose the group are the content of the question in relation to the knowledge and skills of the peers. The model supports the collaboration with text fragments selected from the study materials. We will introduce the model and briefly discuss the results of the calibration and a simulation of the model. Finally, we will discuss the outcome of an experiment with two groups of approximately 50 students, who used the model for a period of 8 weeks. The results indicate that the students positively value the model and that it is possible to solve a substantial number of their questions.