Composing Pieces for Peace: Using Impromptu to Build Cross-Cultural Awareness

Music has long played a role as an ambassador for peace and understanding between cultures. Yet, there is little research that gauges how creating music aids in the development of cross-cultural awareness. Given today’s tense political climate post-9/11, further investigation of the role that music can play in fostering cross-cultural awareness is needed. Using a sociocultural constructionist framework, this study investigated how 22 youth (12 girls and 10 boys) from the United States, in communication with youth in Tel-Aviv, Israel, analyzed and composed music steeped in traditional Hebrew, Arabic, and Western traditions using the computer program, Impromptu. Participants took part in pre-tests and post-tests to measure their awareness and respect for Israelis at the start and end of the study using the Cross-Cultural Awareness Drawing Task (Bar-Tal & Teichman, 2005). Using qualitative techniques, the researchers analyzed the written reflections of participants on their music composition process over the course of the intervention. Findings suggest that the music composition and analysis exercises had a positive impact on the development of crosscultural awareness over time among American students, helping to counter the common misconceptions about the Middle East fostered in today’s media

A Position Effect on the Heritability of Epigenetic Silencing

In animals and yeast, position effects have been well documented. In animals, the best example of this process is Position Effect Variegation (PEV) in Drosophila melanogaster. In PEV, when genes are moved into close proximity to constitutive heterochromatin, their expression can become unstable, resulting in variegated patches of gene expression. This process is regulated by a variety of proteins implicated in both chromatin remodeling and RNAi-based silencing. A similar phenomenon is observed when transgenes are inserted into heterochromatic regions in fission yeast. In contrast, there are few examples of position effects in plants, and there are no documented examples in either plants or animals for positions that are associated with the reversal of previously established silenced states. MuDR transposons in maize can be heritably silenced by a naturally occurring rearranged version of MuDR. This element, Muk, produces a long hairpin RNA molecule that can trigger DNA methylation and heritable silencing of one or many MuDR elements. In most cases, MuDR elements remain inactive even after Muk segregates away. Thus, Muk-induced silencing involves a directed and heritable change in gene activity in the absence of changes in DNA sequence. Using classical genetic analysis, we have identified an exceptional position at which MuDR element silencing is unstable. Muk effectively silences the MuDR element at this position. However, after Muk is segregated away, element activity is restored. This restoration is accompanied by a reversal of DNA methylation. To our knowledge, this is the first documented example of a position effect that is associated with the reversal of epigenetic silencing. This observation suggests that there are cis-acting sequences that alter the propensity of an epigenetically silenced gene to remain inactive. This raises the interesting possibility that an important feature of local chromatin environments may be the capacity to erase previously established epigenetic marks

Gaining insight into cell wall cellulose macrofibril organisation by simulating microfibril adsorption

One of the most important interactions within the paracrystalline matrix of the plant cell wall occurs between cellulose microfibrils to allow for the formation of larger diameter macrofibrils. Here, we have used computational techniques to investigate how different microfibril surfaces might adsorb onto one another. Molecular dynamics simulations show that limited direct adsorption occurs between non-polar surfaces and free energy of desorption calculations suggest this is due to a high energy barrier for the removal of a single layer of water between these surfaces. Further, it is predicted that when microfibril aggregation occurs, significant conformational changes take place at the surfaces of interaction involving O2 dihedral angles, exocyclic C6 conformation, and microfibril chain tilt. It is more likely that direct interactions initially take place between polar (110) surfaces, and that surface interactions occur between the same types of surface, such as 110 to 110, 1–10 to 1–10 or 200 to 100, where hydrogen bonds can be formed, to stabilise the aggregate. Additionally, we have identified that for the exocyclic group of a glucose residue to change conformation in origin layers, the O2 dihedral in residues before and adjacent to the glucose must rotate to a more cis-like conformation, compared to the trans-like conformation observed in crystalline cellulose. This change in exocyclic conformation occurs due to a slight shift in adjacent chains that preferentially stabilises the exocyclic conformation change in a specific glucose residue of each cellobiose repeat

Hydrogen bonds and twist in cellulose microfibrils

There is increasing experimental and computational evidence that cellulose microfibrils can exist in a stable twisted form. In this study, atomistic molecular dynamics (MD) simulations are performed to investigate the importance of intrachain hydrogen bonds on the twist in cellulose microfibrils. We systematically enforce or block the formation of these intrachain hydrogen bonds by either constraining dihedral angles or manipulating charges. For the majority of simulations a consistent right handed twist is observed. The exceptions are two sets of simulations that block the 02-06' intrachain hydrogen bond, where no consistent twist is observed in multiple independent simulations suggesting that the 02-06' hydrogen bond can drive twist. However, in a further simulation where exocyclic group rotation is also blocked, right-handed twist still develops suggesting that intrachain hydrogen bonds are not necessary to drive twist in cellulose microfibrils. (C) 2017 Elsevier Ltd. All rights reserved

Unstable Transcripts in Arabidopsis Allotetraploids Are Associated with Nonadditive Gene Expression in Response to Abiotic and Biotic Stresses

Genome-wide analysis has documented differential gene expression between closely related species in plants and animals and nonadditive gene expression in hybrids and allopolyploids compared to the parents. In Arabidopsis, 15–43% of genes are expressed differently between the related species, Arabidopsis thaliana and Arabidopsis arenosa, the majority of which are nonadditively expressed (differently from mid-parent value) in allotetraploids. Nonadditive gene expression can be caused by transcriptional regulation through chromatin modifications, but the role of posttranscriptional regulation in nonadditive gene expression is largely unknown. Here we reported genome-wide analysis of mRNA decay in resynthesized Arabidopsis allotetraploids. Among ~26,000 annotated genes, over 1% of gene transcripts showed rapid decay with an estimated half-life of less than 60 minutes, and they are called allotetraploid genes with unstable transcripts (AlloGUTs). Remarkably, 30% of alloGUTs matched the nonadditively expressed genes, and their expression levels were negatively correlated with the decay rate. Compared to all genes, these nonadditively expressed alloGUTs were overrepresented 2-6-fold in the Gene Ontology (GOSlim) classifications in response to abiotic and biotic stresses, signal transduction, and transcription. Interestingly, the AlloGUTs include transcription factor genes that are highly inducible under stress conditions and circadian clock regulators that regulate growth in A. thaliana. These data suggest a role of mRNA stability in homoeologous gene expression in Arabidopsis allopolyploids. The enrichment of nonadditively expressed genes in stress-related pathways were commonly observed in Arabidopsis and other allopolyploids such as wheat and cotton, which may suggest a role for stress-mediated growth vigor in hybrids and allopolyploids.The work is supported by the grant from the National Institutes of Health (GM067015). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Cellular and Molecular Biolog