Learn More
Preparing the German Spacelab Mission D-2 project "Gravity Perception and Neuronal Plasticity"--STATEX II--ground based experiments have been performed with larvae of the amphibian vertebrate Xenopus laevis Daud. to study the reactions to different levels of acceleration forces and profiles. The larvae have been exposed to accelerations of up to 5 g for(More)
Cichlid fish larvae were reared from hatching to active free swimming under different gravity conditions: natural environment, increased acceleration in a centrifuge, simulated weightlessness in a clinostat and near weightlessness during space flight. Cytochrome oxidase activity was analyzed semiquantitatively on the ultrastructural level as a marker of(More)
The development of embryonic and larval stages of the South African Toad Xenopus laevis D, was investigated in hyper-g up to 5 g (centrifuge), in simulated 0 g (fast-rotating clinostat), in alternating low g, hyper-g (parabolic flights) and in microgravity (Spacelab missions D1, D-2). The selected developmental stages are assumed to be very sensitive to(More)
The effects of altered gravitational conditions (AGC) on the development of the static vestibulo-ocular reflex (VOR) and readaptation to 1g were investigated in the amphibian Xenopus laevis. Tadpoles were exposed to microgravity during the German Space Mission D-2 for 10 days, using the STATEX closed survival system, or to 3g for 9 days during earth-bound(More)
The effect of long-term (10 days) altered gravitational conditions upon succinate dehydrogenase (SDH) reactivity in total brains as well as in individual brain nuclei of developing cichlid fish larvae had been investigated by means of semiquantitative histochemical methods (densitometric grey value analysis). Increasing accelerations from near(More)
The paper sums up results of a 7-day space flight experiment (D-l-Mission-BW-STA 00-STATEX) using growing frog embryos and larvae (Xenopus laevis) as a model system. Evaluation of photographs taken from the surface of sectioned deep-frozen objects, and micrographs using TEM and SEM show no aberrations in the shape, size, position, or respective electron(More)
  • J Neubert
  • 1979
Electronmicroscopy was used to track the development of the gravity system of frog embryos and larvae which have bred for 5, 7, and 10 d after egg fertilization under conditions of simulated weightlessness on the fast-running horizontal clinostat. Although no differences in the morphologic structure of the organ between test and control animals could be(More)
The effect of long-term (10 days) altered gravitational conditions upon succinate dehydrogenase (SDH) reactivity in total brain as well as in individual brain nuclei of developing cichlid fish larvae has been investigated by means of semiquantitative histochemical methods (densitometric grey value analysis). Increasing acceleration from near weightlessness(More)
This paper builds on initial work on specifying robot motion using human-inspired motor programs. The existing method relies on a series of square wave torque pulses to actuate the robot. Using such pulses to produce motions with a robot will generate large peaks in absolute jerk — change in acceleration per unit time — which can damage the(More)
Aboard the German-Spacelab-Mission D-2 the project "Gravity Perception and Neuronal Plasticity (STATEX II)" was performed. STATEX is for STATolith EXperiment. Objects were growing tadpoles of the South African Toad (Xenopus laevis D.) and a juvenile cichlid fish (Oreochromis mossambicus). The results give a broader base for the understanding of how(More)