465 resultados para primary elements
Resumo:
DNA methylation at promoter CpG islands (CGI) is an epigenetic modification associated with inappropriate gene silencing in multiple tumor types. In the absence of a human pituitary tumor cell line, small interfering RNA-mediated knockdown of the maintenance methyltransferase DNA methyltransferase (cytosine 5)-1 (Dnmt1) was used in the murine pituitary adenoma cell line AtT-20. Sustained knockdown induced reexpression of the fully methylated and normally imprinted gene neuronatin (Nnat) in a time-dependent manner. Combined bisulfite restriction analysis (COBRA) revealed that reexpression of Nnat was associated with partial CGI demethylation, which was also observed at the H19 differentially methylated region. Subsequent genome-wide microarray analysis identified 91 genes that were significantly differentially expressed in Dnmt1 knockdown cells (10% false discovery rate). The analysis showed that genes associated with the induction of apoptosis, signal transduction, and developmental processes were significantly overrepresented in this list (P < 0.05). Following validation by reverse transcription-PCR and detection of inappropriate CGI methylation by COBRA, four genes (ICAM1, NNAT, RUNX1, and S100A10) were analyzed in primary human pituitary tumors, each displaying significantly reduced mRNA levels relative to normal pituitary (P < 0.05). For two of these genes, NNAT and S100A10, decreased expression was associated with increased promoter CGI methylation. Induced expression of Nnat in stable transfected AtT-20 cells inhibited cell proliferation. To our knowledge, this is the first report of array-based "epigenetic unmasking" in combination with Dnmt1 knockdown and reveals the potential of this strategy toward identifying genes silenced by epigenetic mechanisms across species boundaries.
Resumo:
This study investigates how markets for different levels of copper purity are interrelated by testing the long-run price linkage and causalities among the copper futures, primary, copper scrap, and brass scrap markets. It is expected that copper markets that deal with high purity levels, such as the futures, primary, and copper scrap markets, have a long-run relationship. However, brass scrap markets where copper with a lower purity is traded may not have a price linkage with other copper markets. The results reveal that a long-run relationship holds between the futures, primary, and copper scrap markets but the brass scrap market does not have a long-run relationship with the other markets. From the short-run and long-run causality tests, we determine that the futures market plays an important role in transmitting price information to other copper markets while such information flow is not found for the brass scrap market.
Resumo:
This paper is a description of a pilot investigation into conceptions of learning held by a sample of 10 Aboriginal students in a Bachelors degree courses. Results from this study suggest that this group of students view and approach learning in much the same way as other university students. They mostly hold quantitative conceptions of learning and use repetitive strategies which are potentially at odds with the objectives and procedures of the problems based program in which they are studying.
Resumo:
Understanding the organisational processes driving quality primary care is crucial to the maintaining and improving practice. Qualitative methods are increasingly popular in health services research, but this area is dominated by interview studies. Multiple qualitative methods are rarely used in a systematically integrated fashion. We developed a method to study small primary health care organizations using rapid appraisal and qualitative mixed methods: Q-RARA – Qualitative Rapid Appraisal, Rigorous Analysis
Resumo:
Cold-formed steel members have been widely used in residential, industrial and commercial buildings as primary load-bearing and non-load bearing structural elements. These buildings must be properly evaluated after a fire event to assess the nature and extent of structural damage. If the general appearance of the structure is satisfactory after a fire event then the question that has to be answered is how the structural capacity of cold-formed steel members in these buildings has been affected. Elevated temperatures during a fire event affect the structural performance of cold-formed steel members even after cooling down to ambient temperature due to the possible detrimental changes in their mechanical properties. However, the post-fire behaviour of cold-formed steel members has not been investigated in the past and hence there is a need to investigate the post-fire mechanical properties of cold-formed steels. Therefore an experimental study was undertaken at the Queensland University of Technology to understand the residual mechanical properties of cold-formed steels after fire events. Tensile coupon tests were conducted on three different steel grades and thicknesses to obtain their stress-strain curves and relevant mechanical properties after cooling them down from different elevated temperatures. It was found that the post-fire mechanical properties of cold-formed steels are different to the original ambient temperature mechanical properties. Hence a new set of equations is proposed to predict the reduced mechanical properties of cold-formed steels after a fire event.
Resumo:
This presentation tells the story of an initiative in middle schooling at Kelvin Grove State College that begins in the Art studios, but reaches out to other disciplines and approaches, and to community and industry partners. It is inspired by the potential of 'future thinking' to become a compelling focus in contemporary art and design. Ethically it espouses a simple premise": every student in our classrooms now has a stake in creating livable, democratic and creative futures. Every student has the potential to be an active force in making that future. "100 Futures Now" is a project that envisages creative and imaginative students working in collaboration with artists and designers to visualize amazing futures and communicate their vision through art and design. "100 Futures Now" is one in a series of innovative curriculum initiatives at Kelvin Grove State College designed to build sustainable practice in arts education with the support of partners in industry and universities and with resident artists and designers. The model blends elements of art and design methodology to focus on the critical and creative thinking skills prioritised in ACARA and 21st century curriculum. The organisers are developing a sustainable model for working with resident artists that goes beyond a single arts intervention or extension/enrichment experience. In this model artists and designers are collaborators in the design of learning experiences that support future programs. This model also looks to transfer the benefits of residencies to the wider school community (in this case to middle schooling curriculum) and to teachers in other curriculum areas, and not exclusively to the immediate target group. In "100 Futures Now", story-making is the engine that powers the creative process. For this reason the program uses a series of imaginative scenarios, including those of speculative fiction and science, as departure points for inquiry, and applies the methodologies of arts and design practice to explore and express student story telling and story making. The story-making responses of student teams will naturally be expressed multimodally through visual art, design artifacts, installation, performance and digital works. The project’s focus on narratives and its modes of communication (performance/installation) are inspired by the work of experimental contemporary design practices and the speculative scenarios of U.K. based designers Anthony Dunne and Fiona Raby. Thanks to the support of an Arts Queensland Artist-in -Residence grant in 2014, resident artists and designers who work with a diversity of ideas and approaches ranging over science, bio-ethics, biodiversity, behavior and ethics, ambient sound, urbanism, food, and wearable design, will work with middle school students as catalysts for deeper thinking and creative action. All these rich fields for future speculation will become triggers for team inquiry into the deeper connections between the past, the present, and future challenges such as climate, waste, energy, sustainability and resilience. These imagined futures will form the platform for a critical, sustainability/design futures approach that will involve questioning assumptions and empowering students as agents rather than consumers of change.