Food restriction reduces neurogenesis in the avian hippocampal formation

The mammalian hippocampus is particularly vulnerable to chronic stress. Adult neurogenesis in the dentate gyrus is suppressed by chronic stress and by administration of glucocorticoid hormones. Post-natal and adult neurogenesis are present in the avian hippocampal formation as well, but much less is known about its sensitivity to chronic stressors. In this study, we investigate this question in a commercial bird model: the broiler breeder chicken. Commercial broiler breeders are food restricted during development to manipulate their growth curve and to avoid negative health outcomes, including obesity and poor reproductive performance. Beyond knowing that these chickens are healthier than fully-fed birds and that they have a high motivation to eat, little is known about how food restriction impacts the animals' physiology. Chickens were kept on a commercial food-restricted diet during the first 12 weeks of life, or released from this restriction by feeding them ad libitum from weeks 7-12 of life. To test the hypothesis that chronic food restriction decreases the production of new neurons (neurogenesis) in the hippocampal formation, the cell proliferation marker bromodeoxyuridine was injected one week prior to tissue collection. Corticosterone levels in blood plasma were elevated during food restriction, even though molecular markers of hypothalamic-pituitary-adrenal axis activation did not differ between the treatments. The density of new hippocampal neurons was significantly reduced in the food-restricted condition, as compared to chickens fed ad libitum, similar to findings in rats at a similar developmental stage. Food restriction did not affect hippocampal volume or the total number of neurons. These findings indicate that in birds, like in mammals, reduction in hippocampal neurogenesis is associated with chronically elevated corticosterone levels, and therefore potentially with chronic stress in general. This finding is consistent with the hypothesis that the response to stressors in the avian hippocampal formation is homologous to that of the mammalian hippocampus

An Interactive Virtual World Experience - The Cyberspace Roadshow

The goal of this paper is to describe a virtual realtiy application which requires a mobile installation, and the experience gathered during the preparation, realization, and execution of this project. Recently, high-end virtual reality (VR) has received much attention in the marketing field. Professional advertisement agencies are trying to exploit the fascination in this technology raised within the public. IGD was approached by such an agency and requested to prepare a high-quality VR application, serving as a marketing event for the Schweizerische Bankgesellschaft / Union de Banques Suisses (SBG/UBS), the largest Swiss bank. SBG wanted to attract the Swiss youth in order to promote its Junior Bank Card. This event was held in twelve major Swiss cities during four weeks in May/June, 1994, with daily presentations. The time schedule and the marketing concept required a mobile installation. As "Cyberspace Roadshow" the event was advertised in newspapers and radio spots. This was world wide the first mobile, immersive, high-quality VR installation. The complete VR infrastructure was installed in a large truck. The presentations were performed inside the truck as well. The hardware infrastucture was comprised of an image generator (SGI Crimson/RealityEngine), VR geripherals (head-mounted display, data glove, body tracking systems), a sound generator (SGI Indigo), and a large, stereoscopic rear projection screen using polarizing light. Within such an emmersive environment, approximately 40 persons can be involved. Wearing 3D glasses the audience can experience stereoscopic viewing and follow, passively, what one acive person is controlling by utilizing the VR devices. For this event IGD created several entertaining virtual worlds using its proprietary VR system. The main idea was that one active player is flying through a tunnel, approaching a switch room with three alternatives: riding through a jungle, playing musical instruments or exploring a space labyrinth. Each player had a time limit of approximately 5 minutes

Sonification tools to supplement dataflow visualization

Visualization is a widely acknowledged discipline to explore vast numerical data by interactive analysis of their visual representations. General-purpose dataflow visualization systems haveproven their flexibility in many different application domains. Sonification - turning data into audible information - increases the bandwidth of man-machine-communication by one dimension towards a perceptualization platform, which allows the affection of all human senses. The integration of sonification tools in a dataflow visualization system unites the advantages of both directions to a powerful universal visual, aural or audiovisual environment. In this paper a detailled concept for the integration of sonification tools in dataflow systems is presented. An implementation within the apE system and several examples demonstrate the application of the introduced concepts and tools. As print media are ill-suited for aural presentations a video supplement of the results is provided and an integral par t of his work

Acoustic simulation for visualization and virtual reality

Visual presentation can benefit enormously from the integration of acoustic simulations. The combination of visualization and sonification will enable the scientist to perceive quantitatively and analyze qualitatively more data in the same amount of time. With respect to virtual reality the degree of immersion will deepen and the fidelity of virtual worlds will increase significantly. In this report the general appoaches for acoustic simulations, basic mapping and rendering techniques, device utilization, distributed and parallel systems, synchronization of graphical and acoustical presentations and realtime aspects will be explained and discussed