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71.
The immunity protein of colicin E7 (ImmE7) can bind specifically to the DNase-type colicin E7 and inhibit its bactericidal activity. Here we report the 1.8-angstrom crystal structure of the ImmE7 protein. This is the first x-ray structure determined in the superfamily of colicin immunity proteins. The ImmE7 protein consists of four antiparallel alpha-helices, folded in a topology similar to the architecture of a four-helix bundle structure. A region rich in acidic residues is identified. This negatively charged area has the greatest variability within the family of DNase-type immunity proteins; thus, it seems likely that this area is involved in specific binding to colicin. Based on structural, genetic, and kinetic data, we suggest that all the DNase-type immunity proteins, as well as colicins, share a "homologous-structural framework" and that specific interaction between a colicin and its cognate immunity protein relies upon how well these two proteins' charged residues match on the interaction surface, thus leading to specific immunity of the colicin. 相似文献
72.
Driving Automotive User Interface Research 总被引:2,自引:0,他引:2
Cars offer an interesting but challenging microcosm for pervasive computing research and, in particular, for interaction with pervasive computing systems. Increasingly, researchers are looking at interactive applications in the car and investigating human-car interaction from a computer science—rather than an ergonomics or mechanical engineering—perspective. This article reports on the International Conference on Automotive User Interfaces and Interactive Vehicular Applications, wherein participants shared presentations on topics such as aesthetics, user interaction and distraction, safety, and driver monitoring. 相似文献
73.
The separation of mixed auditory signals into their sources is an eminent neuroscience and engineering challenge. We reveal the principles underlying a deterministic, neural network-like solution to this problem. This approach is orthogonal to ICA/PCA that views the signal constituents as independent realizations of random processes. We demonstrate exemplarily that in the absence of salient frequency modulations, the decomposition of speech signals into local cosine packets allows for a sparse, noise-robust speaker separation. As the main result, we present analytical limitations inherent in the approach, where we propose strategies of how to deal with this situation. Our results offer new perspectives toward efficient noise cleaning and auditory signal separation and provide a new perspective of how the brain might achieve these tasks. 相似文献
74.
B. Fuchs W. Kern D. Molle S. Richter P. Rossmanith X. Wang 《Theory of Computing Systems》2007,41(3):493-500
We present a new dynamic programming algorithm that solves the minimum Steiner tree problem on graphs with k terminals in
time O*(ck) for any c > 2. This improves the running time of the previously fastest parameterized algorithm by Dreyfus-Wagner of order
O*(3k) and the so-called "full set dynamic programming" algorithm solving rectilinear instances in time O*(2.38k). 相似文献
75.
76.
The information systems (IS) literature, and the industry sectors confronted with information technology (IT) outsourcing, are beginning to perceive IT outsourcing as more than just a necessary organizational resource-acquisition venture. Instead organizations have begun to consider vendors as their partners, causing many companies to enter into more intricate deals that include both contractual and informal issues. In light of these developments, a growing concern with forming closer client–vendor relationships has evolved for both vendors and clients. This paper explores, in the context of a case study, three critical dimensions emerging from previous studies. These are: what is outsourced; the contract; and the relationship dimension. We also explore the process and management issues underlying these dimensions. The investigation is enabled through two analytical frameworks, one proven in previous research, one exploratory, but both specifically developed for IT outsourcing arrangements. 相似文献
77.
78.
Cemernek David Cemernek Sandra Gursch Heimo Pandeshwar Ashwini Leitner Thomas Berger Matthias Klösch Gerald Kern Roman 《Journal of Intelligent Manufacturing》2022,33(6):1561-1579
Journal of Intelligent Manufacturing - Continuous casting is the most important route for the production of steel today. Due to the physical, mechanical, and chemical components involved in the... 相似文献
79.
Thermal and Electrical Conductivity of Amorphous and Graphitized Carbide‐Derived Carbon Monoliths
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Andreas M. Kern Bodo Zierath Joachim Haertlé Tobias Fey Bastian J. M. Etzold 《化学工程与技术》2016,39(6):1121-1129
The influence of graphitization and composition of carbide‐derived carbon (CDC) monoliths on the electrical and thermal conductivity was investigated. Carbon monoliths with varying porosities were synthesized employing biomorphous macroporous TiC and SiC as precursors. Graphitization was carried out in situ during high‐temperature chlorination with and without addition of nickel, iron, and cobalt chloride to the carbide. The graphitized monoliths showed improved properties. The results demonstrate that despite graphitic carbon also glass‐like carbon, stemming from the carbide synthesis, increases the thermal and electrical conductivity significantly. 相似文献
80.
Yield estimation and forecasting for winter wheat in Hungary using time series of MODIS data 总被引:2,自引:0,他引:2
Péter Bognár Anikó Kern Szilárd Pásztor János Lichtenberger Dávid Koronczay Csaba Ferencz 《International journal of remote sensing》2017,38(11):3394-3414
Wheat is one of the most important crops in Hungary, which represents approximately 20% of the entire agricultural area of the country, and about 40% of cereals. A robust yield method has been improved for estimating and forecasting wheat yield in Hungary in the period of 2003–2015 using normalized difference vegetation index (NDVI) derived from the data of the Moderate Resolution Imaging Spectroradiometer. Estimation was made at the end of June – it is generally the beginning of harvest of winter wheat in Hungary – while the forecasts were performed 1–7 weeks earlier. General yield unified robust reference index (GYURRI) vegetation index was calculated each year using different curve-fitting methods to the NDVI time series. The correlation between GYURRI and country level yield data gave correlation coefficient (r) of 0.985 for the examined 13 years in the case of estimation. Simulating a quasi-operative yield estimation process, 10 years’ (2006–2015) yield data was estimated. The differences between the estimated and actual yield data provided by the Hungarian Central Statistical Office were less than 5%, the average difference was 2.5%. In the case of forecasting, these average differences calculated approximately 2 and 4 weeks before the beginning of harvest season were 4.5% and 6.8%, respectively. We also tested the yield estimation procedure for smaller areas, for the 19 counties (Nomenclature of Territorial Units for Statistics-3 level) of Hungary. We found that, the relationship between GYURRI and the county level yield data had r of 0.894 for the years 2003–2014, and by simulating the quasi-operative forecast for 2015, the resulting 19 county average yield values differed from the actual yield as much as 8.7% in average. 相似文献