Representations of the Klein-Gordon and Dirac propagators are determined in a $N$ dimensional conical background for massive fields twisted by an arbitrary angle $2\pi\sigma$. The Dirac propagator is shown to be obtained from the Klein-Gordon propagator twisted by angles $2\pi\sigma\pm {\cal D}/2$ where ${\cal D}$ is the cone deficit angle. Vacuum expectation values are determined by a point-splitting method in the proper time representation of the propagators. Analogies with the Aharonov-Bohm effect are pointed out throughout the paper and a conjecture on an extension to fields of arbitrary spin is given.Comment: Propagator (11) is rewritten in a more convenient form and the one before that is amended. A more concise expression is given for the energy density of a twisted spinor. The references contain minor correction

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The incidence of Alzheimer's disease is progressively increasing in Wales. Prevalence and incidence rates rise with age. It is important that the public is educated on the symptoms of AD and doctors pay particular attention to these symptoms so as to ensure that diagnosis is made as early as possible. This will enable adequate support to be provided as soon as possible in order to prolong patients' independence and slow the progression of symptoms.

Because it is a small, mobile service that must make the most of every asset, the Marine Corps in the 1940s and early 1950s began to use the utility helicopter as a weapon system. Very quickly it became obvious that the “chopper” offered Corps commanders unprecedented flexibility in moving ground forces much faster than by surface transportation.