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.

Q: Context: Studies over many years have demonstrated that preoptimization and attention to appropriate perioperative care is associated with a substantial decrease in surgical mortality. This review discusses ways in which patient preparation and perioperative support can minimize surgical mortality and morbidity.', 'Scoring systems continue to be developed in order to classify categories of surgical risk. Objective physiologically based assessments can also identify high-risk groups of patients. Debate continues over the indications for specific interventions such as beta-blockade or statin therapy. There is continuing interest in perioperative optimization of oxygen delivery. A multimodality approach paying attention to a range of possible interventions appears to be beneficial. Audit, training, experience and a sufficient volume of procedures are all factors associated with surgical mortality.\Question: Does excellent anaesthesia need patient preparation and postoperative support to influence outcome?

A: The provision of a high-quality service throughout the perioperative period is vital for a successful outcome. Patients need to be assessed well before major elective surgery to determine if they fall into a high-risk category. Some patients may benefit from a change in management. Postoperatively, critical-care support should be available backed by level 1 (enhanced ward) care with input from outreach or medical emergency teams 24 hours per day, seven days a week.
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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?

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.
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Q: Context: Monocarboxylate (MC)-supplemented resuscitation has been shown to attenuate cellular injury after hemorrhagic shock. However, little is known about its effect on the central nervous system. The brain can use MCs such as lactate, pyruvate, and beta-hydroxybutyrate as energy substrates. The transit of MCs into the central nervous system is facilitated by the monocarboxylate transporters (MCTs), and their blockage can exacerbate neuronal damage. We examined the expression of MCT1 and markers specific for activation of astroglia and microglia in the brains of rats subjected to hemorrhagic shock and resuscitation. The hypothesis was that resuscitation with MC-based fluids would be accompanied by MCT1 up-regulation and glial response.', "Rats (n = 30) were subjected to volume-controlled hemorrhage. Test groups included: sham, no resuscitation, resuscitation with normal saline, resuscitation with racemic lactated Ringer's solution, resuscitation with pyruvate Ringer's solution, and resuscitation with beta-hydroxybutyrate-containing ketone Ringer's solution. Plasma levels of MC were measured serially. The brains were investigated using GFAP, CD11b, CD43, MCT1, and GLUT1 immunohistochemistry.", "Rats resuscitated with MC-containing fluids had increased levels of MCT1 in brain endothelial cells and neuropil compared with sham rats. Enhanced staining was localized to the choroid plexus, astrocytic end feet, and white matter structures. None of the resuscitation treatment induced astrocytic hyperplasia, and pyruvate Ringer's solution and ketone Ringer's solution resuscitation led to hypertrophy of astrocytes.\Question: Does energy substrate-supplemented resuscitation affect brain monocarboxylate transporter levels and gliosis in a rat model of hemorrhagic shock?

A:
In hemorrhagic shock, resuscitation with MC-based fluids increased brain MCT1 level and led to activation of astrocytes. Enhanced MC trafficking could be an essential route for energy supply to neurons under adverse circulatory conditions.
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