843 resultados para Conservation of resources theory
Resumo:
Single channel recordings demonstrate that ion channels switch stochastically between an open and a closed pore conformation. In search of a structural explanation for this universal open/close behavior, we have uncovered a striking degree of amino acid homology across the pore-forming regions of voltage-gated K channels and glutamate receptors. This suggested that the pores of these otherwise unrelated classes of channels could be structurally conserved. Strong experimental evidence supports a hairpin structure for the pore-forming region of K channels. Consequently, we hypothesized the existence of a similar structure for the pore of glutamate receptors. In ligand-gated channels, the pore is formed by M2, the second of four putative transmembrane segments. A hairpin structure for M2 would affect the subsequent membrane topology, inverting the proposed orientation of the next segments, M3. We have tested this idea for the NR1 subunit of the N-methyl-D-aspartate receptor. Mutations that affected the glycosylation pattern of the NR1 subunit localize both extremes of the M3-M4 linker to the extracellular space. Whole cell currents and apparent agonist affinities were not affected by these mutations. Therefore it can be assumed that they represent the native transmembrane topology. The extracellular assignment of the M3-M4 linker challenged the current topology model by inverting M3. Taken together, the amino acid homology and the new topology suggest that the pore-forming M2 segment of glutamate receptors does not transverse the membrane but, rather, forms a hairpin structure, similar to that found in K channels.
Resumo:
Cultural heritage sites all over the world are at risk due to aggressive urban expansion, development, wars and general obsolescence. Not all objects are recorded in detail although they may have social and historical significance. For example more emphasis is placed on the recording of castles and palaces than on crofters’ cottages or tenement blocks, although their history can be just as rich. This paper will investigate the historic fabric of Aberdeen through the use of digital scanning, supported by a range of media including old photographs and paintings. Dissemination of social heritage through visualisations will be explored and how this can aid the understanding of space within the city or specific area. Focus will be given to the major statues/monuments within the context of the city centre, exploring their importance in their environment. In addition studying why many have been re-located away from their original site, the reasons why, and how we have perhaps lost some of the social and historical importance of why that monument was first located there. It will be argued that Digital Media could be utilised for much more than re-creation and re-presentation of physical entities. Digital scanning, in association with visualisation tools, is used to capture the essence of both the cultural heritage and the society that created or used the sites in association with visualisation tools and in some way re-enacting the original importance placed upon the monument in its original location, through adoption of BIM Heritage.
Resumo:
This paper proposes a new approach to the study of sociological classics. This approach is pragmatic in character. It draws upon the social pragmatism of G.H. Mead and the sociology of texts of D.F. McKenzie. Our object of study is Norbert Elias’s On the Process of Civilization. The pragmatic genealogy of this book reveals the importance of taking materiality seriously. By documenting the successive entanglements between human agency and non-human factors, we discuss the origins of the book in the 1930s, how it was forgotten for thirty years, and how in the mid-1970s it became a sociological classic. We explain canonization as a matter of fusion between book’s material form and its content, in the context of the paperback revolution of the 1960s, the events of May 1968, and the demise of Parsons’ structural functionalism, and how this provided Elias with an opportunity to advance his model of sociology.
Resumo:
As the new European Commission steps in and looks for ways to promote growth and competitiveness, its success will depend on what emphasis will be given to creating a more sustainable European economy. What will determine the EU’s competitiveness and comparative advantage on a global scene is how well we will respond to the ongoing economic and ecological crises – which are intertwined and reinforce each other. The big question is what emphasis will the new Commission and the EU as a whole give to promoting sustainable and greener growth, based on good management of natural resources and biodiversity, smarter use of resources and mitigating climate change?