When a C programmer needs an efficient data structure for a particular problem, he or she can often simply look one up in any of a number of good textbooks or handbooks. Unfortunately, programmers in functional languages such as Standard ML or Haskell do not have this luxury. Although some data structures designed for imperative languages such as C can be quite easily adapted to a functional se...

Ependymomas are glial tumors derived from ependymal cells lining the ventricles and the central canal of the spinal cord. It may occur outside the ventricular structures, representing the extraventicular form, or without any relationship of ventricular system, called ectopic ependymona. Less than fifteen cases of ectopic ependymomas were reported and less than five were anaplastic. We report a ...

Purely magnetic spacetimes, in which the Riemann tensor satisfies Rabcdu b u d = 0 for some unit timelike vector u, are studied. The algebraic consequences for the Weyl and Ricci tensors are examined in detail and consideration given to the uniqueness of u. Some remarks concerning the nature of the congruence associated with u are made. ∗ Email:[email protected]

The idea of functional programming has played a big role in shaping today’s landscape of mainstream programming languages. Another concept that dominates the current programming style is Dijkstra’s structured programming. Both concepts have been successfully married, for example in the programming language Scala. This paper proposes how the same can be achieved for structured programming and pu...

We study a model for leptogenesis in which the total CP asymmetries in the decays and scatterings involving the SU(2) singlet seesaw neutrinos Nα vanish (ǫNα = 0). Leptogenesis is possible due to non-vanishing CP violating lepton flavor asymmetries, realizing a situation in which the baryon asymmetry is due exclusively to flavor effects. We study the production of a net lepton asymmetry by solv...