University of Wollongong

About: University of Wollongong is a education organization based out in Wollongong, New South Wales, Australia. It is known for research contribution in the topics: Population & Graphene. The organization has 15674 authors who have published 46658 publications receiving 1197471 citations. The organization is also known as: UOW & Wollongong University.

DNA demethylases target promoter transposable elements to positively regulate stress responsive genes in Arabidopsis

Abstract: DNA demethylases regulate DNA methylation levels in eukaryotes. Arabidopsis encodes four DNA demethylases, DEMETER (DME), REPRESSOR OF SILENCING 1 (ROS1), DEMETER-LIKE 2 (DML2), and DML3. While DME is involved in maternal specific gene expression during seed development, the biological function of the remaining DNA demethylases remains unclear. We show that ROS1, DML2, and DML3 play a role in fungal disease resistance in Arabidopsis. A triple DNA demethylase mutant, rdd (ros1 dml2 dml3), shows increased susceptibility to the fungal pathogen Fusarium oxysporum. We identify 348 genes differentially expressed in rdd relative to wild type, and a significant proportion of these genes are downregulated in rdd and have functions in stress response, suggesting that DNA demethylases maintain or positively regulate the expression of stress response genes required for F. oxysporum resistance. The rdd-downregulated stress response genes are enriched for short transposable element sequences in their promoters. Many of these transposable elements and their surrounding sequences show localized DNA methylation changes in rdd, and a general reduction in CHH methylation, suggesting that RNA-directed DNA methylation (RdDM), responsible for CHH methylation, may participate in DNA demethylase-mediated regulation of stress response genes. Many of the rdd-downregulated stress response genes are downregulated in the RdDM mutants nrpd1 and nrpe1, and the RdDM mutants nrpe1 and ago4 show enhanced susceptibility to F. oxysporum infection. Our results suggest that a primary function of DNA demethylases in plants is to regulate the expression of stress response genes by targeting promoter transposable element sequences.

Creative small cities: Rethinking the creative economy in place

Abstract: Whether advocating creativity as a means to place competition or critiquing the social dislocations that stem from creativity-led urban regeneration, research about the creative economy has tended to assume that large cities are the cores of creativity. That many workers in `creative' industries choose to live and work in small urban centres is often overlooked. In this context, this article aims to recover within debates the importance of size, geographical position and class legacies in theories of creativity, economic development and urban regeneration. Using empirical materials from a case study of one Australian city—Wollongong, in New South Wales—it is argued that what might at first appear a rather parochial example illustrates the importance of rethinking the creative economy in place. Crucially, it is shown that, regardless of the numerical population size of a city, creativity is embedded in various complex, competing and intersecting place narratives fashioned by discourses of size, proximity a...

Dietary fats, membrane phospholipids and obesity.

Abstract: Modifications in dietary fat profile have been shown to affect body weight gain and adiposity. This may occur through changes in the partitioning between oxidation and storage and/or alterations in membrane structure, which may in turn influence metabolic rate. All the dietary fat classes are substrates for the biosynthetic elongase and desaturase enzymes. Obesity is associated with increased delta 9 desaturase activity, reduced delta 5 desaturase activity and perhaps reduced delta 6 desaturase activity. Dietary lipid profile can affect the activity of each of these enzymes. A number of possible mechanisms linking dietary fat subtypes with development of obesity are discussed, including modification of sodium potassium pump activity and alterations in mitochondrial proton leakage.

Why some alluvial rivers develop an anabranching pattern

Abstract: Anabranching rivers have been identified globally, but a widely accepted and convincing theoretical explanation for their occurrence has remained elusive Using basic flow and sediment transport relations, this study analyzes the mechanisms whereby self-adjusting alluvial channels can anabranch to alter their flow efficiency (sediment transport capacity per unit of stream power) It shows that without adjusting channel slope, an increase in the number of channels can produce a proportional decrease in flow efficiency, a finding particularly relevant to understanding energy consumption in some braided rivers However, anabranching efficiency can be significantly increased by a reduction in channel width, as occurs when vegetated alluvial islands or between-channel ridges form The counteracting effects of width reduction and an increasing number of channels can cause, with no adjustment to slope, an otherwise unstable system (underloaded or overloaded) to achieve stability As with other river patterns, anabranching can be characterized by stable equilibrium or accreting disequilibrium examples Copyright 2007 by the American Geophysical Union