Hartmut Maass

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In the present study the response to acute saline loading was investigated. During a 24-day study period six male subjects followed a standardized diet including a daily intake of 40 ml water and 125 mg NaCl per kg body weight. Before, during, and after a ten-day period of 6 degrees head down tilt (HDT) each volunteer received an intravenous 0.9% saline(More)
Railway noise interferes with daytime activities and disturbs sleep leading to annoyance of exposed residents. The main objective of this paper was to establish exposure-response relationships between nocturnal railway noise exposure and annoyance and to examine self-reported sleep disturbances as short-term reactions to noise. In a field study 33 residents(More)
We tested the hypothesis that adaptation to microgravity, simulated by a 10-day period of head-down tilt (HDT), alters the responses to an intravenous fluid load by causing a larger fraction of the infused volume to be retained and magnifying the acute hemodynamic effects. HDT caused a significant (p less than 0.01) decrease in blood volume (-0.72 liters)(More)
We studied the effects of head-down tilt bedrest (HDT) on body weight, fluid and sodium homeostasis. A fluid load session with rapid intravenous infusion of 22 ml/kg body weight (BW) isotonic saline was performed before, during and after HDT. During the pre- and post HDT periods the test subjects were given a diet containing 2600 kcal/day. The energy intake(More)
Twenty-two different humoral parameters including stress-, gastrointestinal- and volume-regulating hormones were measured before and within 45 min after parabolic flight maneuvers of twenty healthy adult subjects. We compared hormonal data of motion sickness-affected participants with those unaffected. Changes in cortisol and vasoactive intestinal peptide(More)
Exposures to microgravity and head-down tilt (HDT) produce similar changes in body fluid. This causes an increase in hematocrit that significantly affects hemorheological values. Lack of physical stimulation under bed rest conditions and the relative immobility of the crew during spaceflight also affects the blood fluidity. A group of six healthy male(More)
OBJECTIVE The study was aimed at the examination of the acute and cumulative impact of partial sleep deprivation (PSD) on architecture and quality of sleep, on circadian rhythm and on daytime fatigue. METHODS Time in bed for 16 healthy male volunteers was reduced from 8 to 5h during four consecutive nights, followed by two recovery nights. This scheme(More)
INTRODUCTION: It is a well known fact that noise annoyance depends on the traffic mode. Much less is known about differences in physiological effects, especially on combined effects. Therefore, we investigated the effects of air (AI), road (RO) and rail (RA) traffic noise on sleep in the AIRORA study. METHODS: 72 subjects (40 ± 13 years, 32 male) were(More)
Using the mechanical oscillator technique, the mass density of antecubital venous blood and plasma samples was measured in 6 men before and after infusion of 22 ml/kg isotonic NaCl solution before, on day 7 during, and on day 3 after ten days of 6 degrees head-down bedrest. We studied 1) the distribution volumes of the infused NaCl solution, 2) the(More)