purpose: to investigate indications and methods of surgery in corneal transplantation in labbafinejad medical center from 2007 to 2009. methods: records of 1083 patients who had undergone corneal transplantation from 2007 to 2009 were reviewed. age, sex and indication and type of surgery were evaluated. results: patients included 709 (65.5%) male and 374 (34.5%) female subjects with mean age of...

Molecular phylogenetics, the study of reconstructing evolutionary trees, is a well-established field of scientific endeavor. However, in certain circumstances evolution is not completely tree-like. For example, a comparison of gene trees representing a set of present-day species and reconstructed for different genetic loci often reveals conflicting tree topologies. These discrepancies are not a...

Introduction This paper presents a new description of the maximum parsimony criterion. In particular, this paper demonstrates a new mathematical equivalence between Fitch parsimony as well as selection of certain types of consensus trees. The link between parsimony and consensus is intended to contribute to the discussion on parsimony as well as consensus and total evidence. A link between pars...

This paper deals with several bijections between cladograms and perfect matchings. The first of these is due to Diaconis and Holmes. The second is a modification of the Diaconis-Holmes matching which makes deletion of the largest labeled leaf correspond to gluing together the last two points in the perfect matching. The third is an entirely new encoding of cladograms, first as a bijection with ...

OBJECTIVE The main objectives for this evidence-based analysis were to determine the safety and effectiveness of photochemical corneal collagen cross-linking with riboflavin (vitamin B(2)) and ultraviolet-A radiation, referred to as CXL, for the management of corneal thinning disease conditions. The comparative safety and effectiveness of corneal cross-linking with other minimally invasive trea...