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: Chromatin epigenetics participate in control of gene expression during metazoan development. DNA methylation and post-translational modifications (PTMs) of histones have been extensively characterised in cell types present in, or derived from, mouse embryos. In embryonic stem cells (ESCs) derived from blastocysts, factors involved in deposition of epigenetic marks regulate properties related to self-renewal and pluripotency. In the germ lineage, changes in histone PTMs and DNA demethylation occur during formation of the primordial germ cells (PGCs) to reset the epigenome of the future gametes. Trimethylation of histone H3 on lysine 27 (H3K27me3) by Polycomb group proteins is involved in several epigenome-remodelling steps, but it remains unclear whether these epigenetic features are conserved in non-mammalian vertebrates. To investigate this question, we compared the abundance and nuclear distribution of the main histone PTMs, 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) in chicken ESCs, PGCs and blastodermal cells (BCs) with differentiated chicken ESCs and embryonic fibroblasts. In addition, we analysed the expression of chromatin modifier genes to better understand the establishment and dynamics of chromatin epigenetic profiles.', 'The nuclear distributions of most PTMs and 5hmC in chicken stem cells were similar to what has been described for mammalian cells. However, unlike mouse pericentric heterochromatin (PCH), chicken ESC PCH contained high levels of trimethylated histone H3 on lysine 27 (H3K27me3). In differentiated chicken cells, PCH was less enriched in H3K27me3 relative to chromatin overall. In PGCs, the H3K27me3 global level was greatly reduced, whereas the H3K9me3 level was elevated. Most chromatin modifier genes known in mammals were expressed in chicken ESCs, PGCs and BCs. Genes presumably involved in de novo DNA methylation were very highly expressed. DNMT3B and HELLS/SMARCA6 were highly expressed in chicken ESCs, PGCs and BCs compared to differentiated chicken ESCs and embryonic fibroblasts, and DNMT3A was strongly expressed in ESCs, differentiated ESCs and BCs.\Question: Do chicken embryonic stem cells and primordial germ cells display different heterochromatic histone marks than their mammalian counterparts?
[EX A]: Chicken ESCs and PGCs differ from their mammalian counterparts with respect to H3K27 methylation. High enrichment of H3K27me3 at PCH is specific to pluripotent cells in chicken. Our results demonstrate that the dynamics in chromatin constitution described during mouse development is not universal to all vertebrate species.

[EX Q]: Context: We study the Azospirillum brasilense tolerance to water deficit and the dynamics of adaptive process at the level of the membrane.', 'Azospirillum brasilense was exposed to polyethylene glycol (PEG) growth and PEG shock. Tolerance, phospholipids and fatty acid (FA) composition and membrane fluidity were determined. Azospirillum brasilense was able to grow in the presence of PEG; however, its viability was reduced. Cells grown with PEG showed membrane fluidity similar to those grown without, the lipid composition was modified, increasing phosphatidylcholine and decreasing phosphatidylethanolamine amounts. The unsaturation FAs degree was reduced. The dynamics of the adaptive response revealed a decrease in fluidity 20\xa0min after the addition of PEG, indicating that the PEG has a fluidizing effect on the hydrophobic region of the cell membrane. Fluidity returned to initial values after 60\xa0min of PEG exposure.\Question: Is reorganization of Azospirillum brasilense cell membrane mediated by lipid composition adjustment to maintain optimal fluidity during water deficit?
[EX A]: Azospirillum brasilense is able to perceive osmotic changes by changing the membrane fluidity. This effect is offset by changes in the composition of membrane phospholipid and FA, contributing to the homeostasis of membrane fluidity under water deficit.

[EX Q]: Context: Limited studies have examined ethnic variation in breastfeeding and complementary feeding practices in developing countries. This study investigated ethnic variation in feeding practices in mothers with children 0-23 months old in Vietnam.', 'We used data on 1875 women who came from the ethnic majority, Kinh (n\u2009=\u2009989, randomly sampled from 9875 surveyed Kinh mothers, 10\xa0% from each province) and three ethnic minorities: E De-Mnong (n\u2009=\u2009309), Thai-Muong (n\u2009=\u2009229) and Tay-Nung (n\u2009=\u2009348). Ethnic minorities were compared with the Kinh group using logistic regression model.', 'Prevalence of breastfeeding initiation within an hour of birth was 69\xa0% in Thai-Muong, but ~50\xa0% in other ethnicities. In logistic regression, the prevalence of breastfeeding within one hour was lower in Tay-Nung (OR: 0.54; 95\xa0% CI: 0.38, 0.77) than the majority Kinh. Prevalence of exclusive breastfeeding under 6\xa0months was 18, 10, 17, and 33\xa0% in Kinh, Thai-Muong, Tay-Nung, and E De-Mnong, respectively; compared to the majority Kinh, the prevalence was lower in Thai-Muong (OR: 0.42; 95\xa0% CI: 0.25, 0.71) and higher in E De-Mnong (OR: 1.99; 95\xa0% CI: 1.04, 3.82). Overall prevalence of bottle feeding in Thai-Muong and E De-Mnong (~20\xa0%) was lower than in Kinh (~33\xa0%): Thai-Muong (OR: 0.50; 95\xa0% CI: 0.37, 0.68) and E De-Mnong (OR: 0.69; 95\xa0% CI: 0.50, 0.95). Compared with Kinh (75\xa0%), fewer ethnic minority children received minimum acceptable diets (33\xa0% in Thai-Muong, 46\xa0% in E De-Mnong, and 52\xa0% in Tay-Nung; P\u2009<\u20090.05). Prevalence of minimum acceptable diet (met both dietary frequency and diversity) was lower in Thai-Muong (OR: 0.23; 95\xa0% CI: 0.11, 0.46), Tay-Nung (OR: 0.52; 95\xa0% CI: 0.39, 0.69), and E De-Mnong (OR: 0.55; 95\xa0% CI: 0.33, 0.89) than the majority Kinh.\Question: Do infant and young child feeding practices differ by ethnicity of Vietnamese mothers?
[EX A]:
Breastfeeding practices were suboptimal and differed by ethnicity, which suggests need for tailored interventions at multiple levels to address ethnic-specific challenges and norms. Complementary feeding practices were less optimal among ethnic minorities compared to Kinh, which suggests need for broad intervention including improved food availability, accessibility, and security.