Heinz-Ulrich Krüger

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The in-situ detection of interstellar dust grains in the Solar System by the dust instruments on-board the Ulysses and Galileo spacecraft as well as the recent measurements of hyperbolic radar meteors give information on the properties of the interstellar solid particle population in the solar vicinity. Especially the distribution of grain masses is(More)
AIMS To describe the course of low back pain (LBP) among nurses across eight years. METHODS A longitudinal study was performed with a follow up at 1 and 8 years among nurses employed by a large university hospital in Switzerland. A modified version of the Nordic Questionnaire was distributed to obtain information about demographic data, occupational(More)
A dust cloud of Ganymede has been detected by in-situ measurements with the dust detector onboard the Galileo spacecraft. The dust grains have been sensed at altitudes below five Ganymede radii (Ganymede radius = 2, 635 km). Our analysis identifies the particles in the dust cloud surrounding Ganymede by their impact direction, impact velocity, and mass(More)
The Cinderella hypothesis postulates the continuous activity of specific motor units (MUs) during low-level muscle contraction. The MUs may become metabolically overloaded, with the subject developing muscle pain and strain. The hypothesis requires MUs that are active for a time long enough to actually damage muscle fibers. The aim of this study was to(More)
The effects of a single low alcohol dose (men 0.54 g and women 0.44 g alcohol per kg body weight) were measured by static balance, fine motor activity, and mental performance. In 10 healthy volunteers balance was registered by a temporally and spatially high resolution platform measuring the center of foot pressure and a three-dimensional coordination(More)
The Dust Detector System onboard Galileo records dust impacts in the Jupiter system. Impact events are classified into four quality classes. Class 3 – our highest quality class – has always been noise-free and, therefore, contains only true dust impacts. Depending on the noise environment, class 2 are dust impacts or noise. Within 20RJ from Jupiter (Jupiter(More)
Perceived exertion caused by the extraocular muscles was assessed as a function of the direction of gaze and recorded in 114 subjects using a psychometric method. The results confirm statements in the literature that maximum comfort is achieved when gaze is aimed downwards. We found no correlations between perceived exertion and age or viewing distance. The(More)
OBJECTIVES The study investigated the acute effects of isopropanol exposure at the maximum allowable concentration (MAC) level on the performance of neurobehavioural functions. METHODS In an exposure chamber 20 healthy subjects aged between 21 and 30 years were exposed to isopropanol at a concentration of 400 ppm (Swiss MAC value) for 8 h. A control group(More)
At workplaces with optical aids workers complain more often from visual and musculo-skeletal disorders compared to those working in offices. These complaints concern more often workers using magnifying glasses than those using stereomicroscopes. Bad working-postures at workplaces with loupes and the worse optical quality of todays loupes are two causes. In(More)
Forty-six laser scanner operators were compared with 106 cashiers operating conventional cash registers. The influence of job rotation on the two groups was evaluated, and several design features were examined. For this purpose the prevalence of musculoskeletal disorders was determined by means of a questionnaire and a physical examination. In addition, a(More)