The fundamental role of character coding in Bayesian morphological phylogenetics.

Phylogenetic trees establish a historical context for the study of organismal form and function. Most phylogenetic trees are estimated using a model of evolution. For molecular data, modeling evolution is often based on biochemical observations about changes between character states. For example, there are four nucleotides, and we can make assumptions about the probability of transitions between them. By contrast, for morphological characters, we may not know a priori how many characters states there are per character, as both extant sampling and the fossil record may be highly incomplete, which leads to an observer bias. For a given character, the state space may be larger than what has been observed in the sample of taxa collected by the researcher. In this case, how many evolutionary rates are needed to even describe transitions between morphological character states may not be clear, potentially leading to model misspecification. To explore the impact of this model misspecification, we simulated character data with varying numbers of character states per character. We then used the data to estimate phylogenetic trees using models of evolution with the correct number of character states and an incorrect number of character states. The results of this study indicate that this observer bias may lead to phylogenetic error, particularly in the branch lengths of trees. If the state space is wrongly assumed to be too large, then we underestimate the branch lengths, and the opposite occurs when the state space is wrongly assumed to be too small.

Ablation Compared to Pharmacological Treatment for the Reduction of Atrial Fibrillation Recurrence: A Meta-Analysis.

Atrial fibrillation (AF) is one of the most common heart arrhythmias, and due to its variable presentation, detecting and treating AF appropriately can reduce some of its serious complications. Among treatment options, surgical ablation and antiarrhythmic drug therapy are two of the most widely used choices. A systematic review and meta-analysis were conducted to examine the rates of AF recurrence in those treated with ablation compared to pharmacological treatment. Google Scholar and PubMed were searched for study trials published within the last decade that calculated the recurrence of AF symptoms in patient groups that received ablation or pharmacological treatment. Selected studies were analyzed in RevMan 5.4 software (The Cochrane Collaboration, London, England, UK), and each study's odds ratio and overall odds ratio were calculated using a 95% confidence interval. A total of seven studies with 2324 patients were analyzed for the meta-analysis, with 1162 patients receiving ablation and 1162 patients receiving pharmacological treatment. There was a statistically significant decrease in the recurrence of AF in the ablation group compared to the pharmacological treatment group, with a pooled odds ratio of 0.24 (CI 95% 0.14-0.39). AF treated with ablation was more effective in reducing AF recurrence than general pharmacological treatment.