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: Osteoarthritis (OA) is associated with a gradual reduction in the interstitial osmotic pressure within articular cartilage. The aim of this study was to compare the effects of sudden and gradual hypo-osmotic challenge on chondrocyte morphology and biomechanics.', 'Bovine articular chondrocytes were exposed to a reduction in extracellular osmolality from 327 to 153 mOsmol/kg applied either suddenly (<5 s) or gradually (over 180 min). Temporal changes in cell diameter and the existence of regulatory volume decrease (RVD) were quantified along with changes in cortical actin and chromatin condensation. The cellular viscoelastic mechanical properties were determined by micropipette aspiration.', 'In response to a sudden hypo-osmotic stress, 66% of chondrocytes exhibited an increase in diameter followed by RVD, whilst 25% showed no RVD. By contrast, cells exposed to gradual hypo-osmotic stress exhibited reduced cell swelling without subsequent RVD. There was an increase in the equilibrium modulus for cells exposed to sudden hypo-osmotic stress. However, gradual hypo-osmotic challenge had no effect on cell mechanical properties. This cell stiffening response to sudden hypo-osmotic challenge was abolished when actin organization was disrupted with cytochalasin D or RVD inhibited with REV5901. Both sudden and gradual hypo-osmotic challenge reduced cortical F-actin distribution and caused chromatin decondensation.
Answer: Sudden hypo-osmotic challenge increases chondrocyte mechanics by activation of RVD and interaction with the actin cytoskeleton. Moreover, the rate of hypo-osmotic challenge is shown to have a profound effect on chondrocyte morphology and biomechanics. This important phenomenon needs to be considered when studying the response of chondrocytes to pathological hypo-osmotic stress.
[EX A]: Does the rate of hypo-osmotic challenge influence regulatory volume decrease ( RVD ) and mechanical properties of articular chondrocytes?

[EX Q]: Context: DNA methylation is an important biological form of epigenetic modification, playing key roles in plant development and environmental responses.', 'In this study, we examined single-base resolution methylomes of Populus under control and drought stress conditions using high-throughput bisulfite sequencing for the first time. Our data showed methylation levels of methylated cytosines, upstream 2 kp, downstream 2kb, and repeatitive sequences significantly increased after drought treatment in Populus. Interestingly, methylation in 100 bp upstream of the transcriptional start site (TSS) repressed gene expression, while methylations in 100-2000 bp upstream of TSS and within the gene body were positively associated with gene expression. Integrated with the transcriptomic data, we found that all cis-splicing genes were non-methylated, suggesting that DNA methylation may not associate with cis-splicing. However, our results showed that 80% of trans-splicing genes were methylated. Moreover, we found 1156 transcription factors (TFs) with reduced methylation and expression levels and 690 TFs with increased methylation and expression levels after drought treatment. These TFs may play important roles in Populus drought stress responses through the changes of DNA methylation.
Answer: These findings may provide valuable new insight into our understanding of the interaction between gene expression and methylation of drought responses in Populus.
[EX A]: Do single-base-resolution methylomes of Populus trichocarpa reveal the association between DNA methylation and drought stress?

[EX Q]: Context: In amyotrophic lateral sclerosis (ALS), symptoms apparently spread following regional rules, and depending on the site of onset. We examined if respiratory function deterioration appears earlier or is more severe in patients with upper-limb onset.', 'We compared the results of various pulmonary function tests (PFT) obtained at diagnosis depending on the site of onset in 49 ALS patients. In a longitudinal study, we compared the deterioration of forced vital capacity (FVC) in relation to the site of onset, and analyzed the time elapsed to reach values below 80% of predicted according to site of onset, and we compared the survival depending on the site of onset.', 'No significant differences in PFT were found in the upper-limb onset group in any of the analysis performed. No differences in survival were detected in any disease onset group.
Answer: Pulmonary function deterioration does not appear to be time-linked to arm onset in ALS.
[EX A]:
Is respiratory function deterioration time-linked with upper-limb onset in amyotrophic lateral sclerosis?