Pneumocephalus associated with spinal problems is very rare. Association with encephalomeningitis secondary to a fistula after an infected elective lumbar spine fusion has not been previously reported. The authors report a case in which the clinical onset of pneumoencephalomeningitis occurred after an airplane flight. CT-scan and lumbar puncture were used to make diagnosis; the treatment was ba...

Traditional biology has focused on identifying individual genes, proteins and cells, and studying their specific functions. But that kind of research can yield relatively limited insights about the whole organisms, including the human body. As an analogy, if one wanted to study an airplane, and focused on identifying the engine, wings, and seat belts, and studied their specific functions, one w...

Crosswind gusts can easily disturb the attitude of a small fixed-wing aircraft, potentially causing serious accident during landing or take-off operations. An airplane with high tolerance to crosswind owing quite Clβ and Cnβ values, called Quasi-Neutral Dihedral-effect Directional-stability (QNDD) airplane, was previously proposed. Although design QNDD is more practical than that Neutral (NDD) ...

Nomenclature (contlnued) The paper discusses the development and testing of a real-time Takeoff Performance M Pitching moment (ft_lb) Monitoring System. The algorithm is madeup of two MACH Mach number segments: a pretakeoff segment and a real_time p Roll Rate (rad/sec) segment, q Pitch Rate (rad/sec) One_time inputs of ambient conditions and r Yaw Rate (rad/sec) airplane configuration informati...

We derive optimality conditions for the paths of a Dubins vehicle when the state space is partitioned into two patches with different vehicle’s forward velocity. We recast this problem as a hybrid optimal control problem and solve it using optimality principles for hybrid systems. Among the optimality conditions, we derive a “refraction” law at the boundary of the patches which generalizes the ...

Fauconnier and Turner’s conceptual blending theory (1998) has been used to analyze many types of cognitive phenomena, particularly the role blending plays in language comprehension. In this paper we illustrate how blending also has a role in mediating expert performance, such as understanding the meaning of a chart or a navigation display. Pilots use blends to assess flight situations, predict ...