Traffic into silence: endomembranes and post-transcriptional RNA silencing.

microRNAs (miRNAs) and small interfering RNAs (siRNAs) are small RNAs that repress gene expression at the post-transcriptional level in plants and animals. Small RNAs guide Argonaute-containing RNA-induced silencing complexes to target RNAs in a sequence-specific manner, resulting in mRNA deadenylation followed by exonucleolytic decay, mRNA endonucleolytic cleavage, or translational inhibition. Although our knowledge of small RNA biogenesis, turnover, and mechanisms of action has dramatically expanded in the past decade, the subcellular location of small RNA-mediated RNA silencing still needs to be defined. In contrast to the prevalent presumption that RNA silencing occurs in the cytosol, emerging evidence reveals connections between the endomembrane system and small RNA activities in plants and animals. Here, we summarize the work that uncovered this link between small RNAs and endomembrane compartments and present an overview of the involvement of the endomembrane system in various aspects of RNA silencing. We propose that the endomembrane system is an integral component of RNA silencing that has been long overlooked and predict that a marriage between cell biology and RNA biology holds the key to a full understanding of post-transcriptional gene regulation by small RNAs

Regulation and the roles of art museum education in China and Taiwan

PhD ThesisThis thesis examines the current educational roles of art museums in China and Taiwan under diverse political regimes and social regulation. It is based on case studies of five art museums at both the national and local levels in these two locations. The selection of the case study museums under different levels of governance is aimed at not only identifying the museums’ educational roles, but also understanding how the diverse external influences have shaped the roles of museum education. The data collected through the case studies derives from interviews with the Museum Director and Head of education of each institution, together with non-participatory observations of the educational activities conducted at the case study museums. The thesis is underpinned by the theoretical foundations primarily of Tony Bennett, Antonio Gramsci, Michel Foucault and Pierre Bourdieu. The thesis begins with the adoption of Bennett’s concept on the instrumentality of culture. It takes on Bennett’s view on culture as a constituted field of government, and examines the government policy related to museum education to demonstrate the distinctiveness of culture as a produced surface of social regulation. In this regard, governmental programmes which aim to transform the conduct of the target groups are inscribed into specific cultural institutions. Following this is an investigation into the power-relations of the case study museums based on the concept of governmentality of Foucault. In this approach, the case study museums are viewed as social apparatuses for social management. The practices of the museums are adjusted according to their relationship with their governing bodies and other cultural institutions and organisations involved in these power-relations. The study argues that museums’ educational roles are not only regulated by the ‘top-down’ power from the government, but also the actors who are involved in the field of museum education. To claim this, the analysis chapters investigate the adjustments to the educational roles at the bottom level of the educational practices of the case study museums, based on Bourdieu’s concepts of field, capital and habitus. Finally, the thesis concludes with a comparison of the roles performed by the selected museums at different levels of governance and under diverse political regimes. The study argues that different theoretical frameworks are better suited to understanding one historical period and set of circumstances than another. The Gramscian framework helps us to understand Chinese and Taiwanese cultural policy and practice respectively under past regimes (e.g. under Mao, or under Martial Law), while the Foucauldian and Bourdieuean frameworks allow for a more articulated understanding of the contemporary situation

THE IMPACT OF BSE ON JAPANESE RETAIL BEEF MARKET

To assess the impact of BSE in Japan, a Japanese meat demand system is estimated as a gradual switching Rotterdam model. The results, based on data from April 1994 to May 2002, suggest the structural transition took five months from its discovery. The scare affected both domestic and imported beef.Food Consumption/Nutrition/Food Safety,

US Consumers' Willingness to Pay for Wool Product Attributes

Choice experiments were conducted to assess US consumer demand for woolproduct attributes. The average consumer's WTP was higher for US wool gloves compared to acrylic gloves. For Australian wool gloves, WTP was lower if consumers read information on husbandry practices. Demand for attributes varied across socioeconomic and psychographic characteristics.Demand and Price Analysis,

The Development of Conductive Nanoporous Chitosan Polymer Membrane for Selective Transport of Charged Molecules

We present the development of conductive nanoporous CNT/chitosan membrane for charge-selective transport of charged molecules, carboxylfluorescein (CF), substance P, and tumor necrosis factor-alpha (TNF-α). The membrane was made porous and conductive via gelatin nanoparticle leaching technique and addition of carbon nanotubes, respectively. These nanoporous membranes discriminate the diffusion of positive-charged molecules while inhibiting the passage of negative-charged molecules as positive potential was applied. The permeation selectivity of these membranes is reversed by converting the polarity of applied potential into negative. Based on this principle, charged molecules (carboxylfluorescein, substance P, and TNF-α) are successfully filtered through these membranes. This system shows 30 times more selective for CF than substance P as positive potential was applied, while 2.5 times more selective for substance P than CF as negative potential was applied

The role of dystroglycan in cell adhesion

Dystroglycan is a heterodimeric transmembrane glycoprotein protein of α and β subunits that links the extracellular matrix to the cytoskeleton. Recent data tend to suggest that the role of dystroglycan in non-muscle cells is for cell adhesion, and cytoskeleton reorganisation signalling. To study the relationship between dystroglycan signalling and ERK signalling in focal adhesions, an YFP-ERK construct was expressed in REF52 cells. YFP-ERK was expressed with ERK activity and formed adhesion-like structures in the REF52 cells, however, no ERK activity was detected in the adhesion-like structures in the REF52 cells. To determine the function of dystroglycan for adhesion or cytoskeleton organisation in non-muscle cells, a GFP-tagged full-length dystroglycan (αβDG-GFP) or its deletion mutants was expressed in REF52 cells. Expression of αβDG-GFP markedly altered cell phenotype on a laminin or fibronectin substrate, resulting in the induction of actin-rich filopodia. The β-dystroglycan cytoplasmic domain is determined as the mediator for the dystroglycan-dependent filopodia formation mediated partly by integrin signalling. The dystroglycan deletion mutants lacking α-dystroglycan failed to target to the plasma membrane. Expression of an alkaline phosphate-tagged β-dystroglycan cytoplasmic domain construct (AP-cβ), which targeted the β-dystroglycan cytoplasmic domain to the membrane without the α-dystroglycan, was sufficient to induce the filopodia phenotype, indicating that with the proper membrane localisation, β-dystroglycan can regulate filopodia formation independently of α-dystroglycan. However, α-dystroglycan might be necessary for β-dystroglycan to target to the plasma membrane. These distinct morphologies strongly implied that β-dystroglycan mediates Cdc42 regulated cytoskeleton reorganisation. By cotransfecting dominant negative Cdc42 (Cdc42N17) or constitutively activated Cdc42 (V12Cdc42) constructs with αβDG-GFP or the mutants, Cdc42 was determined to be a mediator for dystroglycan-dependent filopodia formation. Therefore a signalling cycle of dystroglycan-Cdc42-PAK-ezrin-dystroglycan is identified. With this signalling cycle, dystroglycan plays a role in inducing actin filopodia formation and, at the same time, might also inhibit focal adhesion and stress fibre formation

SUVH1, a Su(var)3-9 family member, promotes the expression of genes targeted by DNA methylation.

Transposable elements are found throughout the genomes of all organisms. Repressive marks such as DNA methylation and histone H3 lysine 9 (H3K9) methylation silence these elements and maintain genome integrity. However, how silencing mechanisms are themselves regulated to avoid the silencing of genes remains unclear. Here, an anti-silencing factor was identified using a forward genetic screen on a reporter line that harbors a LUCIFERASE (LUC) gene driven by a promoter that undergoes DNA methylation. SUVH1, a Su(var)3-9 homolog, was identified as a factor promoting the expression of the LUC gene. Treatment with a cytosine methylation inhibitor completely suppressed the LUC expression defects of suvh1, indicating that SUVH1 is dispensable for LUC expression in the absence of DNA methylation. SUVH1 also promotes the expression of several endogenous genes with promoter DNA methylation. However, the suvh1 mutation did not alter DNA methylation levels at the LUC transgene or on a genome-wide scale; thus, SUVH1 functions downstream of DNA methylation. Histone H3 lysine 4 (H3K4) trimethylation was reduced in suvh1; in contrast, H3K9 methylation levels remained unchanged. This work has uncovered a novel, anti-silencing function for a member of the Su(var)3-9 family that has previously been associated with silencing through H3K9 methylation

ESTIMATION THE PREFERENCE OF ECOTOURISM FOR GAOMEI WETLAND IN TAIWAN

Gaomei Wetland is not only the biggest grassy coastal wetland, but also a wild‐animal protecting area, located on the west‐central coast of Taiwan.Wetlands are considered as one of the most important natural resource, which offer a lot of benefits for human and other creatures. However, it is believed that over-intensive recreational activities in Gaomei Wetland should be responsible for serious damages on natural environment and ecosystem. This study takes Gaomei wetland as an example, and aims to estimate its landscape and ecological services values through Choice experiment. The results of this research showed that Gaomei landscape’s economic value is $2.06 million (USD) per year, and$1.54 million (USD) for its value of ecological services. These findings can help to bring up the awareness of natural resource preservation, and hopefully to keep Gaomei Wetland substantial. The results also indicated that visitors with undergraduate degree or above were willing to pay $6.43 (USD) per year for entry fee to enjoy sunset scenery in Gaomei wetland