TASK DEFINITION: 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.
PROBLEM: Context: With male gender as a strong predictor of cardiovascular instability, we hypothesized that gender-specific differences in circulating carbon monoxide levels contributed to dysregulated microvascular function in preterm male infants.', 'Infants born at 24 to 34 weeks of gestation (N = 84) were studied in a regional tertiary neonatal unit. Carboxyhemoglobin levels were measured through spectrophotometry in umbilical arterial blood and at 24, 72, and 120 hours after birth. Microvascular blood flow was determined through laser Doppler flowmetry.', 'Carboxyhemoglobin levels demonstrated a strong inverse relationship with gestational age (r = -0.636; P < .001) and were higher in boys (P = .032). Repeated-measures analysis of variance showed a significant decrease in arterial carboxyhemoglobin levels over time (P < .001), with significant between-subjects effects for gestational age (P = .011) and gender (P = .025). Positive correlations with microvascular blood flow at 24 hours of age (r = 0.495; P < .001) and 120 hours of age (r = 0.548; P < .001) were observed. With controlling for gestational age, carboxyhemoglobin levels at 72 hours were greater for infants who died in the first week of life (P = .035).\Question: Is carbon monoxide a significant mediator of cardiovascular status following preterm birth?

SOLUTION: The gestational age- and gender-specific differences in carboxyhemoglobin levels and the relationship with dysregulated microvascular blood flow, a state related to greater illness severity and hypotension, are novel findings not confined solely to sick preterm infants. Both inducible heme oxygenase-dependent and non-heme oxygenase-dependent pathways may initially play a central role in carbon monoxide production, inducing pathophysiologic processes in a gender-specific manner.

PROBLEM: Context: Magnetic Resonance Imaging (MRI) allows a detailed "in vivo" macroscopic study of the human brain; previously, it has been demonstrated that Fluid Attenuated Inversion Recovery (FLAIR) sequence shows higher signal intensity of cortices belonging to limbic structures.', 'To measure and compare signal intensities (SI) of cytoarchitectonically different cortical regions.', 'In 22 adult subjects, without psychiatric or neurological diseases, FLAIR sequence was performed in coronal slices, perpendicular to the main hippocampal axis. Signal intensity was measured, with a region-of-interest (ROI) function, in 12 different cortical regions. We compared these values and grouped the cortices into five groups: (1) limbic cortices, (2) paralimbic agranular cortices, (3) paralimbic granular cortices, (4) parietal-type neopallium, (5) frontal-type neopallium. A t-test for comparison of paired samples was performed, considering p</=0.05 as statistically significant.', 'We found statistically significant differences amongst the different groups, with the exception of groups 1 and 2, which did not show differences between them. No statistically significant differences were found among cortices belonging to the same group.\Question: Does magnetic resonance imaging identify cytoarchitectonic subtypes of the normal human cerebral cortex?

SOLUTION: Structural characteristics of the cerebral cortex cause changes in its signal intensity. Magnetic resonance imaging (FLAIR sequence) allows discrimination of different cytoarchitectonic areas of the human cerebral cortex.

PROBLEM: Context: Transcription in Escherichia coli generates positive supercoiling in the DNA, which is relieved by the enzymatic activity of gyrase. Recently published experimental evidence suggests that transcription initiation and elongation are inhibited by the buildup of positive supercoiling. It has therefore been proposed that intermittent binding of gyrase plays a role in transcriptional bursting. Considering that transcription is one of the most fundamental cellular processes, it is desirable to be able to account for the buildup and release of positive supercoiling in models of transcription.', "Here we present a detailed biophysical model of gene expression that incorporates the effects of supercoiling due to transcription. By directly linking the amount of positive supercoiling to the rate of transcription, the model predicts that highly transcribed genes' mRNA distributions should substantially deviate from Poisson distributions, with enhanced density at low mRNA copy numbers. Additionally, the model predicts a high degree of correlation between expression levels of genes inside the same supercoiling domain.\Question: Does a biophysical model of supercoiling dependent transcription predict a structural aspect to gene regulation?

SOLUTION:
Our model, incorporating the supercoiling state of the gene, makes specific predictions that differ from previous models of gene expression. Genes in the same supercoiling domain influence the expression level of neighboring genes. Such structurally dependent regulation predicts correlations between genes in the same supercoiling domain. The topology of the chromosome therefore creates a higher level of gene regulation, which has broad implications for understanding the evolution and organization of bacterial genomes.