Sleeping disease (SD), a disease of fresbwater-reared rainbow trout, Oncorhynchus mykiss (Walbaum), was histologically compared to pancreas disease (PD), a disease of seawater-reared Atlantic salmon, Salmo salar L. Some weeks after injection of kidney homogenates from SD-or PD-affected fish in rainbow trout, the fish successively developed pancreatic, heart and muscular lesions in both populations, although the SD-injected population was the most affected. An acquired protection was observed against PD and SD after an initial injection with PD-or SD-infective material. This acquired cross-protection and the similar histopathologies in PD and SD suggest the two diseases could be caused by a similar or identical agent.

BackgroundMany people with mobility impairments, who require the use of powered wheelchairs, have difficulty completing basic maneuvering tasks during their activities of daily living (ADL). In order to provide assistance to this population, robotic and intelligent system technologies have been used to design an intelligent powered wheelchair (IPW). This paper provides a comprehensive overview of the design and validation of the IPW.MethodsThe main contributions of this work are three-fold. First, we present a software architecture for robot navigation and control in constrained spaces. Second, we describe a decision-theoretic approach for achieving robust speech-based control of the intelligent wheelchair. Third, we present an evaluation protocol motivated by a meaningful clinical outcome, in the form of the Robotic Wheelchair Skills Test (RWST). This allows us to perform a thorough characterization of the performance and safety of the system, involving 17 test subjects (8 non-PW users, 9 regular PW users), 32 complete RWST sessions, 25 total hours of testing, and 9 kilometers of total running distance.ResultsUser tests with the RWST show that the navigation architecture reduced collisions by more than 60% compared to other recent intelligent wheelchair platforms. On the tasks of the RWST, we measured an average decrease of 4% in performance score and 3% in safety score (not statistically significant), compared to the scores obtained with conventional driving model. This analysis was performed with regular users that had over 6 years of wheelchair driving experience, compared to approximately one half-hour of training with the autonomous mode.ConclusionsThe platform tested in these experiments is among the most experimentally validated robotic wheelchairs in realistic contexts. The results establish that proficient powered wheelchair users can achieve the same level of performance with the intelligent command mode, as with the conventional command mode.

ABSTRACT. The effects of experimental transmissions of pancreas disease (PD) were compared in Atlantic salmon Salmo salar, rainbow trout Oncorhynchusmykissand brown trout Salmo trutta in fresh water. Only Atlantic salmon developed a total loss of exocrine pancreas acinar cells, which is used to diagnose PD. Brown trout were the least susceptible, exhibiting focal necrosis in an otherwise normalappearing pancreas. The effect in rainbow trout was Intermediate between that seen in salmon and brown trout

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SUMMARYThis paper proposes a new kinematic controller for the waypoints guidance of robotic mobile platforms. A notable feature of the controller is its ability to process the raw sequence of waypoints to produce smooth reference velocities from control laws that are derived by taking into account adriving profileincluding the velocity limits, the acceleration limits, the motion modes through each waypoint (forward or backward) and the precision constraints that are required to ensure accurate waypoints traversal. A mathematical analysis demonstrates the convergence of the movements through the waypoints sequence. In addition, we present a simple way to adapt the driving profile in order that the platform reaches the last waypoint at a prescribed time. A feed-forward unit is finally described, that compensates for delays and first-order poles in the velocity response of the platform. Various simulations and experiments on real robotic platforms demonstrate the behavior and the effectiveness of the solution.