3,468 research outputs found

    A rural agricultural-sustainable energy community model and its application to Felton Valley, Australia

    Get PDF
    Energy and food security require a delicate balance which should not threaten or undermine community prosperity. Where it is proposed to derive energy from conventional fossil fuel resources (such as coal, shale oil, natural gas, coal seam gas) located in established rural areas, and particularly where these areas are used for productive agricultural purposes, there are often both intense community concern as well as broader questions regarding the relative social, economic and environmental costs and benefits of different land uses and, increasingly, different energy sources. The advent of mainstream renewable energy technologies means that alternative energy options may provide a viable alternative, allowing energy demand to be met without compromising existing land uses. We demonstrate how such a Sustainable Energy Rural Model can be designed to achieve a balance between the competing social goals of energy supply, agricultural production, environmental integrity and social well-being, and apply it to the Felton Valley, a highly productive and resilient farming community in eastern Australia. Research into available wind and solar resources found that Felton Valley has a number of attributes that indicate its suitability for the development of an integrated renewable energy precinct which would complement, rather than displace, existing agricultural enterprises. Modelling results suggest a potential combined annual renewable energy output from integrated wind and solar resources of 1,287 GWh/yr from peak installed capacity of 713 MW, sufficient to supply the electrical energy needs of about 160,000 homes, in combination with total biomass food production of 31,000 tonnes per annum or 146 GWh/yr of human food energy. The portfolio of renewable energy options will not only provide energy source diversity but also ensures long-term food security and regional stability. The Felton Valley model provides an example of community-led energy transformation and has potential as a pilot project for the development of smart distributed grids that would negate the need for further expansion of coal mining and coal fired power stations

    Racking Performance of Plasterboard-Clad Steel Stud Walls

    Get PDF
    It is recognised that structural design efficiency in domestic and similar structures can be improved when the composite behaviour and contribution of all materials in the permanent structure can be fully recognised in the structural design of the frame. The ability to achieve this Improvement is currently limited by the need 10 rely on empirical test results for standardised building elements when considering the composite behaviour of the entire structure. The existing test methodology for determining the shear strength of plasterboard lined steel stud walls leads to an excessively conservative design of the complete structure. Since the test configuration is for isolated test panels, the absence of continuity of the plasterboard lining around a set corner is not included in the test procedure. A test program has been devised and carried out to explore the effect of the set corner on the performance of shear test panels. A dramatic improvement in both diaphragm shear strength and shear stiffness has been achieved in these tests supporting a proposal to amend the standard lest methodology to Include set corners

    Regulation of nucleotide excision repair activity by transcriptional and post-transcriptional control of the XPA protein

    Get PDF
    The XPA (Xeroderma pigmentosum A) protein is one of the six core factors of the human nucleotide excision repair system. In this study we show that XPA is a rate-limiting factor in all human cell lines tested, including a normal human fibroblast cell line. The level of XPA is controlled at the transcriptional level by the molecular circadian clock and at the post-translational level by a HECT domain family E3 ubiquitin ligase called HERC2. Stabilization of XPA by downregulation of HERC2 moderately enhances excision repair activity. Conversely, downregulation of XPA by siRNA reduces excision repair activity in proportion to the level of XPA. Ubiquitination and proteolysis of XPA are inhibited by DNA damage that promotes tight association of the protein with chromatin and its dissociation from the HERC2 E3 ligase. Finally, in agreement with a recent report, we find that XPA is post-translationally modified by acetylation. However, contrary to the previous claim, we find that in mouse liver only a small fraction of XPA is acetylated and that downregulation of SIRT1 deacetylase in two human cell lines does not affect the overall repair rate. Collectively, the data reveal that XPA is a limiting factor in excision repair and that its level is coordinately regulated by the circadian clock, the ubiquitin–proteasome system and DNA damage

    Recognition and repair of the cyclobutane thymine dimer, a major cause of skin cancers, by the human excision nuclease

    Get PDF
    The cyclobutane thymine dimer is the major DNA lesion induced in human skin by sunlight and is a primary cause of skin cancer, the most prevalent form of cancer in the Northern Hemisphere. In humans, the only known cellular repair mechanism for eliminating the dimer from DNA is nucleotide excision repair. Yet the mechanism by which the dimer is recognized and removed by this repair system is not known. Here we demonstrate that the six-factor human excision nuclease recognizes and removes the dimer at a rate consistent with the in vivo rate of removal of this lesion, even though none of the six factors alone is capable of efficiently discriminating the dimer from undamaged DNA. We propose a recognition mechanism by which the low-specificity recognition factors, RPA, XPA, and XPC, act in a cooperative manner to locate the lesion and, aided by the kinetic proofreading provided by TFIIH, form a high-specificity complex at the damage site that initiates removal of thymine dimers at a physiologically relevant rate and specificity

    Neural Coding and Synaptic Transmission: Participation Exercises for Introductory Psychology

    Get PDF
    We present two simulations of neural transmission for use in an Introductory Psychology class. These simulations illustrate the complex coding properties of a single neuron, especially how excitatory and inhibitory postsynaptic potentials accumulate to produce an action potential. A follow-up exercise, using the framework of the simple children's game Musical Chairs, illustrates synaptic transmission, including the effects of psychoactive drugs at the synapse.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    The clean air strategy for Alberta : a case study in consensus decision making for sustainable development

    Get PDF
    Thesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 1992.Includes bibliographical references (leaves 98-104).by Carol T. Reardon.M.C.P
    corecore