Fear of flying persistent fear or anxiety when they consider flying, as well as during flying. They will avoid flying if they can, and the fear, anxiety, and avoidance cause significant distress and impair their ability to function. Take-off, bad weather, and turbulence appear to be the most anxiety provoking aspects of flying. The most extreme manifestations can include panic attacks or vomiting at the mere sight or mention of an aircraft or air travel. Around 60% of people with fear of flying report having some other anxiety disorder. The causes of flight phobia and the mechanisms by which it is maintained were
Hurwitz zeta function function of the complex argument "s" ("vide supra"), leading in each case to the difficult study of the zeros of Riemann's zeta function. In particular, there will be no zeros with real part greater than or equal to 1. However, if 0<"q"<1 and "q"≠1/2, then there are zeros of Hurwitz's zeta function in the strip 1<Re("s")<1+ε for any positive real number ε. This was proved by Davenport and Heilbronn for rational or transcendental irrational "q", and by Cassels for algebraic irrational "q". The Hurwitz zeta function occurs in a number of striking identities at rational values. In particular, values in