Mapping evolutionary trajectories of discrete traits onto phylogenies receives considerable attention in evolutionary biology. Given the trait observations at the tips of a phylogenetic tree, researchers are often interested where on the tree the trait changes its state and whether some changes are preferential in certain parts of the tree. In a model-based phylogenetic framework, such question...

RNA-dependent RNA polymerases, the key enzymes in replication of RNA viruses, have a low fidelity; thus, these viruses replicate as a swarm of mutants termed viral quasispecies. Constant generation of new mutations allows RNA viruses to adapt swiftly to a novel environment through selection of both pre-existing and de novo-generated genetic variants. Here, quasispecies dynamics were studied in ...

The ratio of non-synonymous (dN) to synonymous (dS) changes between taxa is frequently computed to assay the strength and direction of selection. Here we note that for comparisons between closely related strains and/or species a second parameter needs to be considered, namely the time since divergence of the two sequences under scrutiny. We demonstrate that a simple time lag model provides a ge...

conclusions our results showed that vitamin d deficiency is more common in patients with ulcerative colitis. laboratory findings confirmed the rise of esr and crp. results our sample comprised of 32 patients with active and 32 patients with silent ulcerative colitis, and 32 age- and sex-matched healthy controls. the frequency of vitamin d deficiency was significantly higher in patients with act...

In India, Holstein and its crosses are being used extensively in breeding programmes and all these breeding bulls are screened for autosomal recessive genes. Blood samples are collected in ethylenediaminetetraacetic acid (EDTA) coated tubes and DNA was isolated by using phenol-chloroform method. Polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) wereperformed by using...

safety issues have always been put forward as one of the major problems and primary concerns in construction industries in many countries. this paper will focus on the impact of safety training on safety climate and its relevant factors in two sites of a construction firm. the health and safety executive (hse) guide to safety climate tool that had been validated in iran was used to determine th...