4,675 research outputs found
PCR-based methods to determine DNA methylation status at specific CpG sites using methylation-sensitive restriction enzymes
ko-ax photo [Selected by Tate Curator of Photography, Simon Baker]
ko-ax photo was an open submission competition selected by Simon Baker (Curator of Photography, Tate), Sue Steward (Photography critic, Telegraph, Observer, Guardian, BBC) and John Gill (Curator Brighton Photo Biennial and Founder Photoworks). The 10 artists selected all presented fascinating artworks that conceal narratives and ask questions of the viewer. Questions of beauty, family, decay and fantasy were all explored across over 50 works.</p
Improved quantification of DNA methylation using methylation-sensitive restriction enzymes and real-time PCR
Heterogeneity of cells with respect to the DNA methylation status at a specific CpG site is a problem when assessing methylation status. We have developed a simple two-step method for the quantification of the percent of cells that display methylation at a specific CpG site in the promoter of a specific gene. The first step is overnight digestion of genomic DNA (optimal conc. 20 ng/5 microl) with a relevant methylation-sensitive restriction enzyme (optimal 2 units). This is followed by real time PCR, using the SYBR Green method, with primers that bracket the site cleaved by the enzyme. By including fully methylated and fully non-methylated DNA in each PCR plate, the errors caused by non-specific digestion or incomplete digestion can be measured and used to adjust the raw results and thus increase specificity. The method can detect differences in methylation status if these are more than 10%. No specialized equipment is required beyond the real-time PCR system and the method can be adapted for any of the 53 commercially available methylation-sensitive restriction enzymes
DNA demethylation at specific CpG sites in the IL1B promoter in response to inflammatory cytokines in human articular chondrocytes
Objective: to determine whether changes in the DNA methylation status in the promoter region of the gene encoding interleukin-1? (IL-1?) account for expression of IL1B mRNA after long-term treatment of human articular chondrocytes with inflammatory cytokines.Methods: IL-1? or TNF? combined with oncostatin M (OSM), or 5-aza-deoxycytidine (5-aza- dC) were added twice weekly for 4-5 weeks to primary cultures of normal human articular chondrocytes, obtained from patients with a femoral neck fracture. Expression of MMP13, IL1B??TNFA and DNMT1 were determined by SybrGreen-based qRT-PCR on genomic DNA and total RNA extracted from the same sample before and after culture. Bisulfite modification was used to identify which CpG sites in the IL1B promoter showed differential methylation between expressing and non-expressing cells. The percentages of cells that were methylated at that critical CpG site (-299bp) were quantified by a method that depended on methylation-sensitive restriction enzymes and real-time PCR. Secretion of IL-1? was assessed by enzyme-linked immunoabsorbent assay (ELISA) of the culture media.Results: healthy chondrocytes did not express IL1B mRNA, but the levels were increased 5-fold by 5-aza-dC and 100- to 1000-fold by or TNF?/OSM. The % CpG methylation was decreased by 5-aza-dC, but reduced considerably more by IL-1? and almost abolished by TNF?/OSM. The mRNA was translated into protein in cytokine-treated chondrocytes.Conclusion: these novel findings indicate that inflammatory cytokines can change DNA methylation status at key CpG sites, resulting in long-term induction of IL1B in human articular chondrocytes.<br/
The people behind the papers – Jason Ko and Daniel Lobo
Planarians grow when they are fed and shrink during periods of starvation. However, it is unclear how they maintain appropriate body proportions as their size changes. A new paper in Development investigates the differences between growth and shrinkage dynamics and builds a mathematical model to explore the mechanisms underpinning these two processes. To learn more about the story behind the paper, we caught up with first author, Jason Ko, and corresponding author, Daniel Lobo, Associate Professor at the University of Maryland.https://doi.org/10.1242/dev.20298
Organizational Learning and Marketing Capability Development: A Study of Charity Retailing Operation of British Social Enterprises
Social enterprise is a hybrid form of profit- and social benefit-seeking organization whereby traditional nonprofit organizations pursue both their social mission and business opportunities. To embrace this new strategic direction shift, the nonprofit organizations need to develop new competences that will enable them to respond to the changes in the business model. The article investigates the learning mechanisms through which social enterprises develop a marketing capability to deploy their resources in the marketplace as the drivers of competitive advantage in their commercial practice. We study eight cases of UK-based charity retailers, in order to address the role of knowledge accumulation, articulation and codification process in the evolution of marketing capability development. We identify, amongst other things that the critical process of organizational learning for social enterprise is to transfer the experience into organization specific knowledge under the social aspects of constraints
Ko au te whenua, te whenua ko au – I am the land, the land is me: An autoethnographic investigation of a secondary school teacher’s experience seeking to enrich learning in outdoor education for Māori students.
This thesis is my story as an outdoor educator, as a researcher, and a co-participant reflecting on my own actions and experiences as well as those of my students. In this autoethnography I share my revelations and tensions in my role as an outdoor education teacher seeking to enrich the experiences of Māori students. Māori culture and history have largely been ignored in the outdoor education classrooms and environments of Aotearoa New Zealand. After teaching the subject for ten years I didn’t perceive that I was perpetuating the same invisibility in my own outdoor education course. Over this time a number of questions that had fermented at the back of my mind came to the fore; ‘why are so few Māori students opting to take outdoor education as a senior secondary school subject?’ and ‘how can I make the subject of outdoor education more desirable and appealing to Māori?’ A place-responsive approach incorporates and values traditional ways of learning through the notion of place and the stories attached to them. The cultural context of learning about and through place has the potential to provide learning opportunities that are relevant and meaningful to all learners but particularly Māori. Place-responsive pedagogies allow outdoor educators to create an environment where language, knowledge, culture and values are normal, valid and legitimate – contexts where Māori students can be themselves. Through this research I have found that the implementation of a place responsive approach has had significant implications for Year twelve outdoor education at Mount Maunganui College. The improvement in Māori student achievement and numbers selecting the subject have been affirming.
Ko au te whenua, te whenua ko au – I am the land, the land is m
KNOWLEDGE ACCUMULATION IN ASIAN PUBLIC ADMINISTRATION RESEARCH: A CRITICAL REVIEW
Given the growing controversy over the relevance of Anglo-Saxon style public administration to developing countries and a greater demand for more context-relevant theories of public administration in Asia, we should expect that Asian scholars achieve a certain level of knowledge growth in line with this controversy and demand. On the basis of the review of 8810 articles published in nine major international journals during 1990-2011, the author found that the number of articles on Asian public administration is very small, and there is no strong pattern of growth in this regard. In addition, there are very few studies adopting a comparative approach covering multiple Asian countries. Copyright (c) 2013 John Wiley & Sons, Ltd.N
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