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81.
This paper presents detailed insights into the nature of innovation dynamics of an SME operating in the food industry. Furthermore, the paper highlights how Action Research has changed and enhanced SME??s capability to innovate. Within the exploratory action research based case study described in this article, the researchers interacted closely with one company with regards to a newly launched innovation process over a time period of more than 18 months. The analysis contributes to the fields of action research and innovation research in three respects: First, it exemplifies how systemic action research as a method can be applied on the organisational level in the private sector. Second, it demonstrates how useful action research can be for fostering the innovativeness and creativity of a company. Lastly, the analysis illustrates the extensive time horizon of an action research project.  相似文献   
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In ancient Athens, the Agora was a place for collective decision making about personal and community issues. New Agoras, most recently Internet-enabled ones, now propose to enliven participatory democracy and establish systems by which our institutions can serve us and we can govern ourselves (B. H. Banathy, Guided Evolution of Society: A Systems View, Kluwer Academic/Plenum Press, New York, 2000). Effective participation in such activity will require a language and consciousness not currently in evidence, and learning beyond current parameters. In this article, high school students from Stephanie Williams' Child Development classes at McDowell High School, Millcreek Township School District, demonstrate use of a new paradigm. This model of Personal Resource Systems Management provides systems language for Agora discourse enabling effective participatory democracy.  相似文献   
83.
Dietary fat is an important source of nutrition. Here we identify eight mutations in SARA2 that are associated with three severe disorders of fat malabsorption. The Sar1 family of proteins initiates the intracellular transport of proteins in COPII (coat protein)-coated vesicles. Our data suggest that chylomicrons, which vastly exceed the size of typical COPII vesicles, are selectively recruited by the COPII machinery for transport through the secretory pathways of the cell.  相似文献   
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The ability of human immunodeficiency virus (HIV-1) to persist and cause AIDS is dependent on its avoidance of antibody-mediated neutralization. The virus elicits abundant, envelope-directed antibodies that have little neutralization capacity. This lack of neutralization is paradoxical, given the functional conservation and exposure of receptor-binding sites on the gp120 envelope glycoprotein, which are larger than the typical antibody footprint and should therefore be accessible for antibody binding. Because gp120-receptor interactions involve conformational reorganization, we measured the entropies of binding for 20 gp120-reactive antibodies. Here we show that recognition by receptor-binding-site antibodies induces conformational change. Correlation with neutralization potency and analysis of receptor-antibody thermodynamic cycles suggested a receptor-binding-site 'conformational masking' mechanism of neutralization escape. To understand how such an escape mechanism would be compatible with virus-receptor interactions, we tested a soluble dodecameric receptor molecule and found that it neutralized primary HIV-1 isolates with great potency, showing that simultaneous binding of viral envelope glycoproteins by multiple receptors creates sufficient avidity to compensate for such masking. Because this solution is available for cell-surface receptors but not for most antibodies, conformational masking enables HIV-1 to maintain receptor binding and simultaneously to resist neutralization.  相似文献   
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Mallik R  Carter BC  Lex SA  King SJ  Gross SP 《Nature》2004,427(6975):649-652
Cytoskeletal molecular motors belonging to the kinesin and dynein families transport cargos (for example, messenger RNA, endosomes, virus) on polymerized linear structures called microtubules in the cell. These 'nanomachines' use energy obtained from ATP hydrolysis to generate force, and move in a step-like manner on microtubules. Dynein has a complex and fundamentally different structure from other motor families. Thus, understanding dynein's force generation can yield new insight into the architecture and function of nanomachines. Here, we use an optical trap to quantify motion of polystyrene beads driven along microtubules by single cytoplasmic dynein motors. Under no load, dynein moves predominantly with a mixture of 24-nm and 32-nm steps. When moving against load applied by an optical trap, dynein can decrease step size to 8 nm and produce force up to 1.1 pN. This correlation between step size and force production is consistent with a molecular gear mechanism. The ability to take smaller but more powerful strokes under load--that is, to shift gears--depends on the availability of ATP. We propose a model whereby the gear is downshifted through load-induced binding of ATP at secondary sites in the dynein head.  相似文献   
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Shcheprova Z  Baldi S  Frei SB  Gonnet G  Barral Y 《Nature》2008,454(7205):728-734
Ageing and the mortality that ensues are sustainable for the species only if age is reset in newborns. In budding yeast, buds are made young whereas ageing factors, such as carbonylated proteins and DNA circles, remain confined to the ageing mother cell. The mechanisms of this confinement and their relevance are poorly understood. Here we show that a septin-dependent, lateral diffusion barrier forms in the nuclear envelope and limits the translocation of pre-existing nuclear pores into the bud. The retention of DNA circles within the mother cell depends on the presence of the diffusion barrier and on the anchorage of the circles to pores mediated by the nuclear basket. In accordance with the diffusion barrier ensuring the asymmetric segregation of nuclear age-determinants, the barrier mutant bud6Delta fails to properly reset age in buds. Our data involve septin-dependent diffusion barriers in the confinement of ageing factors to one daughter cell during asymmetric cell division.  相似文献   
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The genome of the model beetle and pest Tribolium castaneum   总被引:6,自引:0,他引:6  
Tribolium castaneum is a member of the most species-rich eukaryotic order, a powerful model organism for the study of generalized insect development, and an important pest of stored agricultural products. We describe its genome sequence here. This omnivorous beetle has evolved the ability to interact with a diverse chemical environment, as shown by large expansions in odorant and gustatory receptors, as well as P450 and other detoxification enzymes. Development in Tribolium is more representative of other insects than is Drosophila, a fact reflected in gene content and function. For example, Tribolium has retained more ancestral genes involved in cell-cell communication than Drosophila, some being expressed in the growth zone crucial for axial elongation in short-germ development. Systemic RNA interference in T. castaneum functions differently from that in Caenorhabditis elegans, but nevertheless offers similar power for the elucidation of gene function and identification of targets for selective insect control.  相似文献   
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