in this article we introduce the notion of n-capable groups. it is shown that every group g admits a uniquely determined subgroup (〖z^n)〗^* (g) which is a characteristic subgroup and lies in the n-centre subgroup of the group g. this is the smallest subgroup of g whose factor group is n-capable. moreover, some properties of n-central extension will be studied.

Background: The simultaneous existence of two different abnormalities in a gene is referred to double heterozygosity. The most common form of it is the association of thalassemia and sickle cell disease, being termed sickle cell thalassemia. The aim of this research was to study all of the hemoglobinopathies in thalassemia major patients in Lorestan Province. Materials and methods: This st...

It is well known that the statistical characteristics of a language, such as word frequency or the consistency of the relationships between orthography and phonology, influence literacy acquisition. Accordingly, linguistic databases play a central role by compiling quantitative and objective estimates about the principal variables that affect reading and writing acquisition. We describe a new s...

Magnuson, McMurray, Tanenhaus, and Aslin [Cogn. Sci. 27 (2003) 285] suggest that they have evidence of lexical feedback in speech perception, and that this evidence thus challenges the purely feedforward Merge model [Behav. Brain Sci. 23 (2000) 299]. This evidence is open to an alternative explanation, however, one which preserves the assumption in Merge that there is no lexical–prelexical feed...

One difficulty with this logic is that included in the criteria for identifying abuse was the failure of the parents to explain the fractures. Although the lack of an explanation may be a pointer to nonaccidental injury, it is also a characteristic feature of fractures caused by bone diseases such as osteogenesis imperfecta, bone disease of prematurity, and, indeed, rickets.4 Thus, the criteria...