It is generally assumed that in catching a fly ball, an efficient strategy for dealing with the horizontal component of the ball's trajectory is for the observer to keep the angular position of the ball constant with respect to his head. That strategy is called the constant bearing angle or CBA strategy. Maintenance of angular constancy results in the simultaneous arrival of both observer and ball at the landing spot. The authors analyzed the approach behavior of 26 subjects in a ball-interception task with straight paths for both the subjects and the ball. Subjects moved at a velocity that maintained a close-to-constant horizontal angular position of the ball with respect to the end effector throughout the approach phase rather than a constant bearing angle with respect to their head. Velocity adaptations occurred as a function of the changes in the angular velocity of the ball in such a way that a positive or negative angular velocity was canceled. Thus, an actor following the CBA strategy does not need to know where and when the ball will arrive (i.e., a predictive strategy), because reliance on the CBA strategy ensures that he will make the appropriate adaptations that enable him to arrive at the right place in the right time.

The purpose of this study was to examine the role of background texture on an interception task during self-motion. Twenty-six participants modulated tricycle speed along one arm of a V-shaped track so as to intercept a ball approaching horizontally on the other arm of the V. Either a plain or a textured background (consisting of contrasting vertical stripes) was used. Velocity modulations occurred so as to keep the angle beta between the direction of heading and the line head-ball constant (constant bearing angle, or CBA strategy), indicating that this observer-environment relation might regulate the approach phase. In the textured condition, participants initially drove faster than predicted by the CBA model and compensated by slowing down in the second half. This is in line with the texture-induced overestimation of the ball velocity and implies that absolute velocity information is also used.

Radiocesium contamination of air, rain, grass, milk and humans in Belgium from the late 1950s to present was measured. The main sources of fallout were atmospheric nuclear weapons tests and the Chernobyl accident; in Belgium the average impact of the first on the human body burden was more than six times higher. The geographical distribution of radiocesium fallout in Belgium was surveyed by means of in-situ gammaspectrometry with HPGe detectors.

The presence of depleted uranium in the soil of former Yugoslavia after the 1999 conflict raised great public concern all over the world. The so-called Balkan-syndrome is often linked with depleted uranium contamination. An excellent compilation of data about DU and its possible impact on health and environment can be found in the 1999 UNEP report and publications from the Swedish Radiation Protection Institute. Unfortunately, very few systematic and reliable data on the possible depleted uranium concentrations were until now available. Some of these rare data are only available on the web, without adequate information about the experimental procedure used. To clarify the situation, a systematic survey was started in the summer of 2000 as a collaborative effort between Ghent University (Physics Laboratory) and the Belgian Ministry of Defense (Medical Service). From 50 sites selected all over Kosovo, 150 soil samples were measured in the laboratory with a high-resolution gamma-spectrometer. Some sites (14) were explicitly selected based on military information on the use of depleted uranium munitions in the vicinity. After careful analysis we can conclude that there is no indication of any depleted uranium contamination on these 50 sites with a minimal detectable activity of 15 Bq; this corresponds approximately to 1 mg depleted uranium in a typical sample (100-150 g).