For a function from the unit interval to itself with constant slope and one discontinuity, the itineraries of the point of discontinuity are called the critical itineraries. These critical itineraries play a significant role in the study of β-expansions (with positive or negative β) and fractal transformations. A combinatorial characterization of the critical itineraries of such functions is pr...

We build up normal ordered products for fermionic open string coordinates consistent with boundary conditions. The results are obtained considering the presence of antisymmetric tensor fields. We find a discontinuity of the normal ordered products at string endpoints even in the absence of the background. We discuss how the energy momentum tensor also changes at the world-sheet boundary in such...

Research demonstrates that police reduce crime. We study this question by using a natural experiment in which a private university increased the number of police patrols within an arbitrarily defined geographic boundary. Capitalizing on the discontinuity in patrols at the boundary, we estimate that the extra police decreased crime in adjacent city blocks by 43–73%. Our results are consistent wi...

in sustainable agriculture, using of resistant plants is one of the best methods for integrated pest management. resistance of 140 rice promising lines against striped stem borer was evaluated in two planting date in the field under natural infections in sari agricultural science and natural resources university during 2008-2009. this study carried out as a factorial experiment in randomized co...

synthetic plants as well as wild crop species are valuable genetic resourses. to determine the genetic variation in triticale, tritipyrum as well as wheat lines, genomic dna of this amphiploid including thinopyrum bessarabicum and durum wheat were amplified using 32 random and 22 semi random primers. primers that could produce clear, polymorphic and repetitive bands are used for determination o...

Overhead transmission lines are influenced by different factors which are mostly electrical and mechanical. These factors can cause problems for lines, distortions in network and outage of line. In designing transmission lines mechanical properties are evaluated after selecting a suitable conductor and clearance with regard to electrical properties. In lines designing, an important mechanical p...