The clustering pattern in the tree is consistent with the functional diversification and differentiation of the histone subtypes based on a birth-and-death model of evolution [ 28], ruling out a major effect of a concerted evolution mechanism.
Alternatively, researchers could choose to run molecular clock analyses in which the prior on the node ages is not based on a birth-death process, but modeled using uniform or Dirichlet distributions [ 55, 56], as implemented in e.g. Multidivtime [ 57] and PhyloBayes [ 58].
The TBTC is based on a birthing center model and aims to attract Tibetan and other women who would not normally deliver in a hospital, by providing high-quality obstetric/gynecologic care in a home-like environment.
5 In our recent survey 9 based on a complete birth population of more than 61 000 birth registries (total birth rate 11.3‰) in Huai'an, Jiangsu province in 2010, we found a perinatal mortality of 7.7‰, a neonatal mortality of 4.4‰ in all live births, a preterm rate of 3.72% with 7.61% mortality, and a low birth weight (LBW) of 2.8% with 8.83% mortality.
The study was a nested case control study based on a national birth cohort.
The data was based on a large birth cohort, which is also definitely another strength of this study.
The age specific population was based on a 2011 birth cohort experiencing current rates of natural mortality.
The study is derived from the Finnish Prenatal Study of Autism (FIPS-A), which is a nested case control study based on a national birth cohort, and aims to identify early life risk factors of ASD.
Based on a live birth rate of 20% and a minimal clinical important difference of 7,5% (one-sided alpha 2,5%, beta 20%) a total of 1150 patients will be needed.
