Kidney transplantation is the therapy of choice for patients with end stage renal disease. Graft survival is optimal when donor and recipient are fully match for the human leukocyte antigens (HLA), however due to the high degree of polymorphism of HLA, in most situation, this is not possible. Therefore haploidentical (partially matched) siblings, parents or off-spring are considered as potentia...

BACKGROUND Delayed or even lack of healing of a split-thickness skin graft (STSG) donor site is a potential problem with elderly patients or those with poor wound healing capabilities. A proactive solution that may minimize this risk is to regraft that donor site using otherwise discarded skin graft remnants. METHODS A prospective, nonrandomized, consecutive study was designed to compare the ...

Bayesian Markov chain Monte Carlo (MCMC) has become one of the principle methods of performing phylogenetic inference. Implementing the Markov chain Monte Carlo algorithm requires the definition of a proposal distribution which defines a transition kernel over the state space. The precise form of this transition kernel has a large impact on the computational efficiency of the algorithm. In this...

Phylogenetic networks have emerged as a unifying evolutionary model of both vertical and horizontal inheritance. A major approach for reconstructing such networks is to reconcile gene trees that are reconstructed from various genomic regions. The Subtree Prune and Regraft (SPR) operation has been used to obtain lower bound estimates of the number of reticulation events from a pair of trees. How...

Please send further problems/challenges/conectures to Mike Steel Combinatorial Challenge I: Walking through trees Submitted by David Bryant An " NNI-­‐walk " is a sequence T1, T2, …, Tk of unrooted binary phylogenetic trees where each consecutive pair of trees differ by a single NNI. i. [Question] What is the shortest NNI walk that passes through all binary trees on n leaves? ii. [Question] Sup...

Horizontal gene transfer (HGT) is one of the main mechanisms driving the evolution of microorganisms. Its accurate identification is one of the major challenges posed by reticulate evolution. In this article, we describe a new polynomial-time algorithm for inferring HGT events and compare 3 existing and 1 new tree comparison indices in the context of HGT identification. The proposed algorithm c...

Leaf-labelled trees are widely used to describe evolutionary relationships, particularly in biology. In this setting, extant species label the leaves of the tree, while the internal vertices correspond to ancestral species. Various techniques exist for reconstructing these evolutionary trees from data, and an important problem is to determine how “far apart” two such reconstructed trees are fro...

Phylogenetic trees illustrate the evolutionary history of genes and species. In most cases, although genes evolve along with the species they belong to, a species tree and gene tree are not identical, because of evolutionary events at the gene level like duplication or transfer. These differences are handled by phylogenetic reconciliation, which formally is a mapping between gene tree nodes and...

Phylogenetic trees are a commonly used tool for representing the relationships between species in an evolutionary system, especially in evolutionary biology. A central task in the study of these trees is to determine which among a set of hypothesised trees gives the best explanation of empirical data. However, finding the trees that optimize some criterion is often computationally prohibitive b...

BACKGROUND & OBJECTIVES Endothelial cells of the donor cornea are known to be affected quantitatively and qualitatively in different pathological conditions after penetrating keratoplasty (PK) and this has direct effect on the clarity of vision obtained after PK. This study was undertaken to analyze the qualitative and quantitative changes in donor endothelial cells before and after PK in diffe...