Given a passage with a context and an answer, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

[EX Q]: Context: Before desflurane is advocated for patients undergoing neurosurgical procedures, it is necessary to determine the effect of desflurane on cerebral blood flow (CBF). In this study, CBF values are compared between desflurane and isoflurane at two doses. In addition, CBF reactivity to CO2 and the effect of prolonged exposure were compared between the two agents.', 'Cerebral blood flow measurements with intravenous 133Xe were performed in 24 patients undergoing craniotomy for mass lesions, randomized to receive either isoflurane or desflurane in oxygen and air. Cerebral blood flow was determined at 1 and 1.5 MAC concentrations at PaCO2 of 25 mmHg in the absence of surgical stimulation. Intraoperatively, with 1.25 MAC anesthesia, CBF was determined at target PaCO2 of 25 and 35 mmHg. In 15 patients, an additional measurement at 1.25 MAC was made before closure.', 'At 1.0 MAC, mean +/- SD CBF values for the desflurane and isoflurane groups were 18 +/- 2 and 20 +/- 3 ml x 100 g-1 x min-1, respectively. At 1.5 MAC, CBF values were the same for the two anesthetics; 17 +/- 3 ml x 100 g-1 x min-1 for isoflurane and 19 +/- 4 ml.100 g-1 x min-1 for desflurane. During 1.25 MAC anesthesia, there were no differences between groups, with CO2 reactivity 1.3 +/- 1.2 ml x 100 g-1 x min-1 x mmHg-1 for desflurane and 1.6 +/- 0.6 ml.100 g-1 x min-1 x mmHg-1 for isoflurane. There was no demonstrable decrease in CBF with prolonged exposure to either agent.
Answer: Desflurane and isoflurane are similar in terms of absolute CBF, the response to increasing doses, and the preservation of CO2 reactivity.
[EX A]: Do desflurane and isoflurane have similar effects on cerebral blood flow in patients with intracranial mass lesions?

[EX Q]: Context: Bacteria often form multicellular, organized communities known as biofilms, which protect cells from a variety of environmental stresses. During biofilm formation, bacteria secrete a species-specific matrix; in Bacillus subtilis biofilms, the matrix consists of protein polymers and exopolysaccharide. Many domesticated strains of B. subtilis have a reduced ability to form biofilms, and we conducted a two-month evolution experiment to test whether laboratory culturing provides selective pressure against biofilm formation in B. subtilis.', 'Bacteria grown in two-month-long batch culture rapidly diversified their biofilm-forming characteristics, exhibiting highly diverse colony morphologies on LB plates in the initial ten days of culture. Generally, this diversity decreased over time; however, multiple types of colony morphology remained in our final two-month-old populations, both under shaking and static conditions. Notably, while our final populations featured cells that produce less biofilm matrix than did the ancestor, cells overproducing biofilm matrix were present as well. We took a candidate-gene approach to identify mutations in the strains that overproduced matrix and found point mutations in the biofilm-regulatory gene sinR. Introducing these mutations into the ancestral strain phenocopied or partially phenocopied the evolved biofilm phenotypes.
Answer: Our data suggest that standard laboratory culturing conditions do not rapidly select against biofilm formation. Although biofilm matrix production is often reduced in domesticated bacterial strains, we found that matrix production may still have a fitness benefit in the laboratory. We suggest that adaptive specialization of biofilm-forming species can occur through mutations that modulate biofilm formation as in B. subtilis.
[EX A]: Is sinR a mutational target for fine-tuning biofilm formation in laboratory-evolved strains of Bacillus subtilis?

[EX Q]: Context: Body-focused attention is regarded as an important maintaining factor for somatoform illness, although there is limited empirical evidence pertaining to this hypothesis. This study was conducted to assess whether individual differences in somatoform dissociation and somatosensory amplification were associated with biased attention towards the tactile modality, particularly following exposure to threatening body-related stimuli.', 'Forty-eight nonclinical participants completed the Somatoform Dissociation Questionnaire (SDQ-20; a proxy measure of somatoform symptomatology), the Somatosensory Amplification Scale (SSAS), and a modality bias task. The task consisted of a series of body-relevant or body-irrelevant (scene) picture stimuli, half of which were threatening and half were neutral, followed by target stimuli in either the visual or the tactile modality. Participants judged the location of each target stimulus, and performance data were used to calculate the degree to which participants were biased towards the tactile modality following each of the picture types.', 'Participants in the high SDQ-20 group (defined by median split) showed a significant increase in tactile bias when responding to targets occurring 250 ms after the presentation of threatening body-relevant stimuli only. This effect was not observed for the low SDQ-20 group. Scores on the SSAS correlated negatively with tactile bias for both threatening and neutral body-relevant stimuli at 250 ms.
Answer: Individuals with a tendency to experience somatoform symptoms focus more on stimuli in the tactile modality immediately following exposure to threatening body-relevant information. In contrast, self-reported somatosensory amplification appears to be associated with attention away from the tactile modality rather than with increased tactile focus.
[EX A]:
Are somatoform dissociation and somatosensory amplification differentially associated with attention to the tactile modality following exposure to body-related stimuli?