In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

[EX Q]: Context: The aim of this study was to evaluate the effect of local injection of vasopressin on blood loss and secondary impact on complications during cesarean section in patients with placenta previa.', 'We retrospectively reviewed the medical records of all patients diagnosed with placenta previa admitted to our hospital. Two consecutive periods were compared. During period B, 59 patients underwent the local injection of a vasopressin solution (4 U in 20 mL of saline) into the placental implantation site after placental delivery. During period A, 50 patients underwent cesarean section without vasopressin injection, and were analyzed as a control group. The estimated blood loss was recorded, as were the complications during surgery. In addition, the expression of the vasopressin V1α receptor in uterine smooth muscle was evaluated by immunohistochemistry.', 'The mean estimated blood loss was significantly lower in the vasopressin group than in the control group. There were no statistically significant differences with surgical complications. The vasopressin V1α receptor was highly expressed in smooth muscle cells in the lower segment of the uterine body, whereas the immunoreactivity for the oxytocin receptor was faint in the lower segment.\Question: Does local injection of vasopressin reduce the blood loss during cesarean section in placenta previa?
[EX A]: The local injection of vasopressin into the placental implantation site significantly reduced the blood loss without increasing the morbidity.

[EX Q]: Context: Although current molecular clock methods offer greater flexibility in modelling evolutionary events, calibration of the clock with dates from the fossil record is still problematic for many groups. Here we implement several new approaches in molecular dating to estimate the evolutionary ages of Lacertidae, an Old World family of lizards with a poor fossil record and uncertain phylogeny. Four different models of rate variation are tested in a new program for Bayesian phylogenetic analysis called TreeTime, based on a combination of mitochondrial and nuclear gene sequences. We incorporate paleontological uncertainty into divergence estimates by expressing multiple calibration dates as a range of probabilistic distributions. We also test the reliability of our proposed calibrations by exploring effects of individual priors on posterior estimates.', 'According to the most reliable model, as indicated by Bayes factor comparison, modern lacertids arose shortly after the K/T transition and entered Africa about 45 million years ago, with the majority of their African radiation occurring in the Eocene and Oligocene. Our findings indicate much earlier origins for these clades than previously reported, and we discuss our results in light of paleogeographic trends during the Cenozoic.\Question: Does integration of Bayesian molecular clock methods and fossil-based soft bounds reveal early Cenozoic origin of African lacertid lizards?
[EX A]: This study represents the first attempt to estimate evolutionary ages of a specific group of reptiles exhibiting uncertain phylogenetic relationships, molecular rate variation and a poor fossil record. Our results emphasize the sensitivity of molecular divergence dates to fossil calibrations, and support the use of combined molecular data sets and multiple, well-spaced dates from the fossil record as minimum node constraints. The bioinformatics program used here, TreeTime, is publicly available, and we recommend its use for molecular dating of taxa faced with similar challenges.

[EX Q]: Context: Hemodynamic disturbed flow (DF) is associated with susceptibility to atherosclerosis. Endothelial Kruppel-Like Factor 4 (KLF4) is an important anti-inflammatory atheroprotective transcription factor that is suppressed in regions of DF.', 'The plasticity of epigenomic KLF4 transcriptional regulation by flow-mediated DNA methylation was investigated in vitro and in arterial tissue.', 'To recapitulate dominant flow characteristics of atheroprotected and atherosusceptible arteries, human aortic endothelial cells were subjected to pulsatile undisturbed flow or oscillatory DF containing a flow-reversing phase. Differential CpG site methylation was measured by methylation-specific polymerase chain reaction, bisulfite pyrosequencing, and restriction enzyme-polymerase chain reaction. The methylation profiles of endothelium from disturbed and undisturbed flow sites of adult swine aortas were also investigated. In vitro, DF increased DNA methylation of CpG islands within the KLF4 promoter that significantly contributed to suppression of KLF4 transcription; the effects were mitigated by DNA methyltransferase (DNMT) inhibitors and knockdown of DNMT3A. Contributory mechanisms included DF-induced increase of DNMT3A protein (1.7-fold), DNMT3A enrichment (11-fold) on the KLF4 promoter, and competitive blocking of a myocyte enhancer factor-2 binding site in the KLF4 promoter near the transcription start site. DF also induced DNMT-sensitive propathological expression of downstream KLF4 transcription targets nitric oxide synthase 3, thrombomodulin, and monocyte chemoattractant protein-1. In support of the in vitro findings, swine aortic endothelium isolated from DF regions expressed significantly lower KLF4 and nitric oxide synthase 3, and bisulfite sequencing of KLF4 promoter identified a hypermethylated myocyte enhancer factor-2 binding site.\Question: Does hemodynamic disturbed flow induce differential DNA methylation of endothelial Kruppel-Like Factor 4 promoter in vitro and in vivo?
[EX A]:
Hemodynamics influence endothelial KLF4 expression through DNMT enrichment/myocyte enhancer factor-2 inhibition mechanisms of KLF4 promoter CpG methylation with regional consequences for atherosusceptibility.