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The development of a sustainable energy system throughout an enterprise is a complex task, which requires an agile holistic approach. Such an approach needs to include a variety of objectives including energy strategy formation and strategic decision-making, which are directly related to the analysis and management of the main areas of sustainable development:The economic, technological, environmental, and social. These multidimensional requirements of sustainability are often difficult to achieve within the enterprise, because these aspects are interrelated and influenced by various internal and external environment factors. This paper first reviews the main challenges for an energy system, and then demonstrates how a strategic agile enterprise architecture driven approach could effectively guide the sustainable energy system development. The study presented in this paper provides a holistic approach that contributes to the advancement and usage of literature dealing with issues of sustainable energy system development and agile enterprise architecture, which has not been discussed before to any great extent. 相似文献
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BS Kendrick BS Chang T Arakawa B Peterson TW Randolph MC Manning JF Carpenter 《Canadian Metallurgical Quarterly》1997,94(22):11917-11922
Understanding the mechanism for sucrose-induced protein stabilization is important in many diverse fields, ranging from biochemistry and environmental physiology to pharmaceutical science. Timasheff and Lee [Lee, J. C. & Timasheff, S. N. (1981) J. Biol. Chem. 256, 7193-7201] have established that thermodynamic stabilization of proteins by sucrose is due to preferential exclusion of the sugar from the protein's surface, which increases protein chemical potential. The current study measures the preferential exclusion of 1 M sucrose from a protein drug, recombinant interleukin 1 receptor antagonist (rhIL-1ra). It is proposed that the degree of preferential exclusion and increase in chemical potential are directly proportional to the protein surface area and that, hence, the system will favor the protein state with the smallest surface area. This mechanism explains the observed sucrose-induced restriction of rhIL-1ra conformational fluctuations, which were studied by hydrogen-deuterium exchange and cysteine reactivity measurements. Furthermore, infrared spectroscopy of rhlL-1ra suggested that a more ordered native conformation is induced by sucrose. Electron paramagnetic resonance spectroscopy demonstrated that in the presence of sucrose, spin-labeled cysteine 116 becomes more buried in the protein's interior and that the hydrodynamic diameter of the protein is reduced. The preferential exclusion of sucrose from the protein and the resulting shift in the equilibrium between protein states toward the most compact conformation account for sucrose-induced effects on rhIL-1ra. 相似文献
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Entrainment and musicality in the human system interface 总被引:1,自引:1,他引:0
Satinder P. Gill 《AI & Society》2007,21(4):567-605
What constitutes our human capacity to engage and be in the same frame of mind as another human? How do we come to share a sense of what ‘looks good’ and what ‘makes sense’? How do we handle differences and come to coexist with them? How do we come to feel that we understand what someone else is experiencing? How are we able to walk in silence with someone familiar and be sharing a peaceful space? All of these aspects are part of human ‘interaction’. In designing interactive technologies designers have endeavoured to explicate, analyse and simulate, our capacity for social adaptation. Their motivations are mixed and include the desires to improve efficiency, improve consumption, to connect people, to make it easier for people to work together, to improve education and learning. In these endeavours to explicate, analyse and simulate, there is a fundamental human capacity that is beyond technology and that facilitates these aspects of being, feeling and thinking with others. That capacity, we suggest, is human entrainment. This is our ability to coordinate the timing of our behaviours and rhythmically synchronise our attentional resources. Expressed within the movements of our bodies and voices, it has a quality that is akin to music. In this paper, disparate domains of research such as pragmatics, social psychology, behaviourism, cognitive science, computational linguistics, gesture, are brought together, and considered in light of the developments in interactive technology, in order to shape a conceptual framework for understanding entrainment in everyday human interaction. 相似文献
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Because many testicular toxicants cause damage to specific stages of spermatogenesis, the present study has investigated the utility of a model in which the testis is synchronized to contain only a few closely related spermatogenic stages. The susceptibility of different stages to 1,3-dinitrobenzene (1,3-DNB) toxicity was investigated in rats, the testes of which had been stage synchronized by a vitamin A depletion/repletion (VADR) procedure. 1,3-DNB (25 mg/kg, IP) or vehicle was injected 58, 61, or 78 d after vitamin A readministration, and testicular histopathology was evaluated 48 h later. At the time of sacrifice, testes in the three groups were synchronized to stages I-VI, VII-IX, or X-XIV+I. The data indicated that tubules in all stages of spermatogenesis, in both synchronized and unsynchronized animals, demonstrated histopathologic changes in response to 1,3-DNB. However, the lesion seen in synchronized animals was more severe and less stage specific than that seen in weight-matched, unsynchronized animals. This increase in degree of susceptibility could be partially explained by differences in toxicokinetics. Stage-synchronized testes could provide unique insights into stage-specific cellular and molecular events, especially for in vitro studies where the stage enrichment could be maximally exploited. However, results obtained from in vivo toxicity studies using animals subjected to VADR should be interpreted carefully in light of the confounding physiologic/metabolic perturbations potentially induced by the VADR procedure. 相似文献
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A deletion mutant of the catalytic RNA component of Escherichia coli RNase P missing residues 87-241 retains the ability to interact with the protein component to form a functional catalyst. The deletion of this phylogenetically conserved region significantly increases the Km, indicating that the deleted structures may be important for binding to the precursor tRNA substrate but not for the cleavage reaction. Under some reaction conditions, this RNase P deletion mutant can become a relatively non-specific nuclease, indicating that this RNA's catalytic center may be more exposed. The catalytic core of the RNase P is formed by less than one third of the 377 residues of the RNase P RNA. 相似文献
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Effects of Na+ and Mg2+ on the structures of supercoiled DNAs: comparison of simulations with experiments 总被引:3,自引:0,他引:3
JA Gebe JJ Delrow PJ Heath BS Fujimoto DW Stewart JM Schurr 《Canadian Metallurgical Quarterly》1996,262(2):105-128
Recent cryo-electron microscopy (cryo-EM) results suggest that sufficient NaCl concentration (> or approximately 0.1 M) and superhelix density (> or approximately-0.05) cause circular DNAs to adopt highly extended, tightly interwound configurations, in which the strands are laterally contiguous along almost their entire length. Millimolar levels of MgCl2 reportedly act synergistically with NaCl to produce similar conformations. However, Monte Carlo simulations with purely repulsive interduplex forces failed to reproduce such structures. In the present work, solution measurements of particular physical properties were performed both to characterize the effects of Na+ and Mg2+ on DNA structure and to provide quantitative tests of Monte Carlo simulations of circular DNAs. Supercoiled p30 delta DNAs in 10 mM Tris plus 0, 0.122, and 0.1 M NaCl, and 0.1 M NaCl plus 4 mM Mg2+ were examined by static and dynamic light scattering (LS and DLS), time-resolved fluorescence polarization anisotropy (FPA) of intercalated ethidium, and circular dichroism (CD) spectroscopy. Upon addition of 0.122 M NaCl, the radius of gyration (Rg) decreased substantially, which indicates that p30 delta adopts a more compact structure. This contradicts the cryo-EM studies, where molecular extension and Rg both increase upon adding 0.1 M NaCl. In 0.1 M NaCl, the torsion constant measured by FPA is practically invariant to superhelix density, and the plateau diffusion coefficient at large scattering vector (Dplat) is likewise nearly the same at both relaxed and native superhelix densities. Such invariance is difficult to reconcile with any transition from relaxed circles to tightly interwound structures with laterally contiguous strands. Metropolis Monte Carlo simulations were performed to generate canonically distributed sets of structures, from which average Do values and scattered intensity ratios, [symbol: see text]I (zero) [symbol: see text]/[symbol: see text] l(k) [symbol: see text], were calculated. Agreement between simulations and experiments in regard to [symbol: see text] I(O) [symbol: see text] /[symbol: see text] I(k) [symbol: see text], D(zero) and the supercoiling free energy, delta Gsc (delta l), is remarkably good for the most extensively studied p30 delta samples. The simulated structures exhibit no sign of very tight interwinding with extensive lateral contacts, but instead exhibit most probable superhelix diameters of 85 to 90 A. When 4 mM Mg2+ was added to native supercoiled p30 delta in 0.1 M NaCl, Rg decreased, D(zero) increased, and the longest internal relaxation rate (1/tau 2(zero)) increased, all of which indicate a further overall contraction of the molecular envelope. The torsion constant exhibited a slight increase that is hardly statistically significant. In this case, agreement between the simulations and experiments was only semi-quantitative for most samples investigated, although the predicted contraction was exhibited by all five samples of p30 delta and one of pBR322 DNA. The simulated structures in 0.1 M NaCl plus 4 mM Mg2+ again showed no sign of extensive lateral contacts. A plausible explanation is proposed for the highly extended, tightly interwound structures seen in cryo-EM, and explicitly tested by Monte Carlo simulations of a 1000 bp circular DNA at +25 and -50 degrees C. Structures identical to those seen in cryo-EM are in fact the equilibrium structures in the simulations at -50 degrees C, and the estimated time for equilibration (2.3 x 10(-6) second) is much smaller than the estimated time for vitrification (1 x 10(-4) second). 相似文献