2,306 research outputs found

    Resource-based View in Information Systems Research: A Meta-Analysis

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    Resource-based view is the theory that has been applied to analyze the impact of informa-tion technology on business performance. Its main argument is that competitive advan-tages are determined by the unique valuable resources controlled by an organization. IT as a valuable asset will have positive effect on firm performance. However, previous re-search on the issue is inconsistent. This paper reports a meta analysis of 42 papers pub-lished in major journals in information systems. Our findings indicate that the capability mediated model is better than the direct effect model and the major impact of IT is on ef-ficiency indicators

    Attosecond pulse carrier-envelope phase effects on ionized electron momentum and energy distributions

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    We analyze carrier-envelope phase (CEP) effects on electron wave-packet momentum and energy spectra produced by one or two few-cycle attosecond xuv pulses. The few-cycle attosecond pulses are assumed to have arbitrary phases. We predict CEP effects on ionized electron wave-packet momentum distributions produced by attosecond pulses having durations comparable to those obtained by Sansone et al. [Science 314, 443 (2006)]. The onset of significant CEP effects is predicted to occur for attosecond pulse field strengths close to those possible with current experimental capabilities. Our results are based on single-active-electron solutions of the three-dimensional, time-dependent Schrödinger equation including atomic potentials appropriate for the H and He atoms

    Proteomic changes associated with deletion of the Magnaporthe oryzae conidial morphology-regulating gene COM1

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    <p>Abstract</p> <p>Background</p> <p>The rice blast disease caused by <it>Magnaporthe oryzae </it>is a major constraint on world rice production. The conidia produced by this fungal pathogen are the main source of disease dissemination. The morphology of conidia may be a critical factor in the spore dispersal and virulence of <it>M. oryzae </it>in the field. Deletion of a conidial morphology regulating gene encoding putative transcriptional regulator COM1 in <it>M. oryzae </it>resulted in aberrant conidial shape, reduced conidiation and attenuated virulence.</p> <p>Results</p> <p>In this study, a two-dimensional gel electrophoresis/matrix assisted laser desorption ionization- time of flight mass spectrometry (2-DE/MALDI-TOF MS) based proteomics approach was employed to identify the cellular and molecular components regulated by the COM1 protein (COM1p) that might contribute to the aberrant phenotypes in <it>M. oryzae</it>. By comparing the conidial proteomes of <it>COM1 </it>deletion mutant and its isogenic wild-type strain P131, we identified a potpourri of 31 proteins that exhibited statistically significant alterations in their abundance levels. Of these differentially regulated proteins, the abundance levels of nine proteins were elevated and twelve were reduced in the Δ<it>com1 </it>mutant. Three proteins were detected only in the Δ<it>com1 </it>conidial proteome, whereas seven proteins were apparently undetectable. The data obtained in the study suggest that the COM1p plays a key role in transcriptional reprogramming of genes implicated in melanin biosynthesis, carbon and energy metabolism, structural organization of cell, lipid metabolism, amino acid metabolism, etc. Semi-quantitative RT-PCR analysis revealed the down-regulation of genes encoding enzymes involved in melanin biosynthesis in the <it>COM1 </it>mutant.</p> <p>Conclusions</p> <p>Our results suggest that the COM1p may regulate the transcription of genes involved in various cellular processes indispensable for conidial development and appressorial penetration. These functions are likely to contribute to the effects of COM1p upon the aberrant phenotypes of <it>M. oryzae</it>.</p> <p>Reviewers</p> <p>This article is reviewed by George V. Shpakovski, Karthikeyan Sivaraman (nominated by M. Madan Babu) and Lakshminarayan M. Iyer.</p

    Photodetachment of H\u3csup\u3e-\u3c/sup\u3e by a short laser pulse in crossed static electric and magnetic fields

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    We present a detailed quantum mechanical treatment of the photodetachment of H- by a short laser pulse in the presence of crossed static electric and magnetic fields. An exact analytic formula is presented for the final state electron wave function (describing an electron in both static electric and magnetic fields and a short laser pulse of arbitrary intensity). In the limit of a weak laser pulse, final state electron wave packet motion is examined and related to the closed classical electron orbits in crossed static fields predicted by Peters and Delos [Phys. Rev. A 47, 3020 (1993)]. Owing to these closed orbit trajectories, we show that the detachment probability can be modulated, depending on the time delay between two laser pulses and their relative phase, thereby providing a means to partially control the photodetachment process. In the limit of a long, weak pulse (i.e., a monochromatic radiation field) our results reduce to those of others; however, for this case we analyze the photodetachment cross section numerically over a much larger range of electron kinetic energy (i.e., up to 500 cm-1) than in previous studies and relate the detailed structures both analytically and numerically to the above-mentioned, closed classical periodic orbits
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