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51.
Current interest in ad hoc and peer-to-peer networking technologies prompts a re-examination of models for configuration management within these frameworks. In the future, network management methods may have to scale to millions of nodes within a single organization, with complex social constraints. In this paper, we discuss whether it is possible to manage the configuration of large numbers of network devices using well known and not so well known configuration models, and we discuss how the special characteristics of ad hoc and peer-to-peer networks are reflected in this problem. 相似文献
52.
F Tarantini T LaVallee A Jackson S Gamble C Mouta Carreira S Garfinkel WH Burgess T Maciag 《Canadian Metallurgical Quarterly》1998,273(35):22209-22216
The heparin-binding fibroblast growth factor (FGF) prototypes lack a classical signal sequence, yet their presence is required in the extracellular compartment for the activation of cell-surface receptor-dependent signaling. Early studies with FGF-1 demonstrated its presence in bovine brain as a novel high molecular weight complex, and subsequent studies identified a second heparin-binding protein that co-purified with FGF-1. Polypeptide sequence analysis revealed that this heparin-binding protein corresponded to the extravesicular domain of bovine synaptotagmin (Syn)-1, a transmembrane component of synaptic vesicles involved in the regulation of organelle traffic. Since FGF-1 is released in response to heat shock as a mitogenically inactive Cys-30 homodimer, we sought to determine whether this heparin-binding protein was involved in the release of FGF-1. We report that a proteolytic fragment of the extravesicular domain of Syn-1 is associated with FGF-1 in the extracellular compartment of FGF-1-transfected NIH 3T3 cells following temperature stress. By using heparin-Sepharose affinity to discriminate between the monomer and homodimer forms of FGF-1 and resolution by conventional and limited denaturant gel shift immunoblot analysis, it was possible to identify FGF-1 and Syn-1 as potential components of a denaturant- and reducing agent-sensitive extracellular complex. It was also possible to demonstrate that the expression of an antisense-Syn-1 gene represses the release of FGF-1 in response to heat shock. These data indicate that FGF-1 may be able to utilize the cytosolic face of conventional exocytotic vesicles to traffic to the inner surface of the plasma membrane where it may gain access to the extracellular compartment as a complex with Syn-1. 相似文献
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55.
L Rao DP Jones LH Nguyen SA McMahan RR Burgess 《Canadian Metallurgical Quarterly》1996,241(2):173-179
The pathogenic Neisseria have exploited the processes of horizontal DNA transfer and genetic recombination as mechanisms for the generation of extensive protein variation and modulation of gene expression. Localized recombinations have been well documented in members of multigene families as have alterations in short repetitive sequences. Here we report an analysis of the chromosomal structure of a defined lineage of Neisseria gonorrhoeae strain MSl1 pilin variants. This study reveals the occurrence of large rearrangements, including the amplification of a 26 kb region and an inversion involving more than a third of the chromosome. Additionally, a restriction site polymorphism that correlates with pilin expression has been observed. These findings highlight the flexibility of the gonococcal genome. 相似文献
56.
Spanos Nicholas P.; Burgess Cheryl A.; Cross Patricia A.; MacLeod Geoffrey 《Canadian Metallurgical Quarterly》1992,101(1):192
Examined the role of reporting bias in hypnotic negative hallucinations by using a paradigm in which reporting bias was assessed independently of perceptual change. In Exp 1, highly hypnotizable Ss reported significant loudness reductions when tested for hypnotic deafness. Later, however, these Ss biased their reported loudness reductions in the absence of perceptual change, and their reporting bias scores were almost as large as their hypnotic deafness reports. Ss also biased their ratings of strategy use. In Exp 2, ratings of blindness given in response to a hypnotic negative visual hallucination suggestion were significantly correlated with reporting bias scores obtained in this paradigm. Although hypnotic blindness and hypnotic deafness correlated significantly, the partial correlation between these variables was nonsignificant when reporting bias scores were statistically controlled. Theoretical implications are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
57.
CK Goldman L Soroceanu N Smith GY Gillespie W Shaw S Burgess G Bilbao DT Curiel 《Canadian Metallurgical Quarterly》1997,15(5):462-466
The r?le of chemotherapy in the treatment of operable soft tissue sarcomas is still debatable. In high-grade tumors, randomized trials using adjuvant chemotherapy have resulted in controversial results. A recent meta-analysis showed a higher median disease-free survival in groups with chemotherapy compared to controls. Doxorubicin, ifosfamide and dacarbazine are the majors drugs. Their combination in adjuvant treatment is currently being investigated. Neoadjuvant chemotherapy has allowed conservative surgery in initially unoperable tumors, but its role in primarily operable tumors remains to be defined. 相似文献
58.
Wine distillery wastewaters (WDW) are acidic and have a high content of potential organic pollutants. This causes high chemical oxygen demand (COD) values. Polyphenols constitute a significant portion of this COD, and limit the efficiency of biological treatment of WDWs. WDW starting parameters were as follows: pH 3.83, 4,185 mg/l soluble COD (COD(s)) and 674.6 mg/l of phenols. During operation, amendments of CaCO3 and K2HPO4, individually or in combination, were required for buffering the digester. Volatile fatty acid concentrations were < 300 mg/l throughout the study, indicating degradation of organic acids present. Mean COD(s) removal efficiency for the 130 day study was 87%, while the mean polyphenol, removal efficiency was 63%. Addition of 50 mg/l Fe(3+) between days 86 and 92 increased the removal efficiencies of COD(s) to 97% and of polyphenols to 65%. Addition of Co(3+) improved removal efficiencies to 97% for COD(s) and 92% for polyphenols. Optimization of anaerobic treatment was achieved at 30% WDW feed strength. Removal efficiencies of 92% and 84% were recorded at increased feed strength from days 108 to 130. High removal efficiencies of COD(s) and polyphenols after day 82 were attributed to the addition of macronutrients and micronutrients that caused pH stability and thus stimulated microbial activity. 相似文献
59.
KR Burgess 《Canadian Metallurgical Quarterly》1998,3(1):1-11
The three-dimensional (3-D) structure of a RNA pseudoknot that causes the efficient ribosomal frameshifting in the gag-pro region of mouse mammary tumor virus (MMTV) has been determined recently by nuclear magnetic resonance (NMR) studies. But since the structure refinement in the studies did not use metal ions and waters, it is not clear how metal ions participate in the stabilization of the pseudoknot, and what kind of ion-RNA interactions dominate in the tertiary contacts for the RNA pseudoknotting. Based on the reported structure data of the pseudoknot VPK of MMTV, we gradually refined the structure by restrained molecular dynamics (MD) using NMR distance restraints. Restrained MD simulation of the RNA pseudoknot was performed with sodium ions and water molecules. Our results are in good agreement with known NMR data and delineate the importance of the metal ion coordination in the stability of the pseudoknot. In the non-coaxially stacking pseudoknot, stem 1 (S1), stem 2 (S2), and the intervening A14 involves unconventional stacking of base pairs coordinated by Na+ and/or bridging water molecules. A6 and G7 of loop L1 make a perfect base stacking in the major groove and are further stabilized by coordinated Na+ ions and water molecules. The first 4-nucleotide (nt) ACUC of loop L2 form a sharp turn and the following 4-nt AAAA cross the minor groove of S1 and are steadied by interactions with the nucleotides of S , bridging water molecules and coordinated Na+ ions. Our studies suggest that the metal ion plays a crucial role in the RNA pseudoknotting of VPK. In the stacking interior of S1 and S2, the Na+ ion is positioned in the major groove and interacts directly with the carbonyl group O6 of G28 and carbonyl group O4 of U13 in the wobble base pair U13:G28. The ion-RNA interactions in MMTV VPK not only stabilize the RNA pseudoknot but also modify the electrostatic properties of the nucleotides at the critical parts of the pseudoknot VPK. 相似文献
60.
This study demonstrates the use of supercritical carbon dioxide in the removal of residual carbon tetrachloride from chlorinated polyisoprene in a packed column. The effects of varying temperature and pressure on the efficiency of extraction are examined. The data indicate that there exists an optimum combination of pressure and temperature and that quite small deviations from these conditions can produce substantially poorer extraction efficiency and lead to the destruction of the polymer particle morphology. 相似文献