6,925 research outputs found

    Engineering Bureaucracy: The Genesis of Formal Policies, Positions, and Structures in High-Technology Firms

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    [Excerpt] This article examines the impact of organizational founding conditions on several facets of bureaucratization—managerial intensity, the proliferation of specialized managerial and administrative roles, and formalization of employment relations. Analyzing information on a sample of technology start-ups in California\u27s Silicon Valley, we characterize the organizational models or blueprints espoused by founders in creating new enterprises. We find that those models and the social composition of the labor force at the time of founding had enduring effects on growth in managerial intensity (i.e., reliance on managerial and administrative specialists) over time. Our analyses thus provide compelling evidence of path dependence in the evolution of bureaucracy—even in a context in which firms face intense selection pressures—and underscore the importance of the logics of organizing that founders bring to new enterprises. We find less evidence that founding models exert persistent effects on the formalization of employment relations or on the proliferation of specialized senior management titles. Rather, consistent with neo-institutional perspectives on organizations, those superficial facets of bureaucracy appear to be shaped by the need to satisfy external gatekeepers (venture capitalists and the constituents of public corporations), as well as by exigencies of organizational scale, growth, and aging. We discuss some implications of these results for efforts to understand the varieties, determinants, and consequences of bureaucracy

    Inertia and Change in the Early Years: Employment Relations in Young, High Technology Firms

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    [Excerpt] This paper considers processes of organizational imprinting in a sample of 100 young, high technology companies. It examines the effects of a pair of initial conditions: the founders\u27 models of the employment relation and their business strategies. Our analyses indicate that these two features were well aligned when the firms were founded. However, the alignment has deteriorated over time, due to changes in the distribution of employment models. In particular, the \u27star\u27 model and \u27commitment\u27 model are less stable than the \u27engineering\u27 model and the \u27factory\u27 model. Despite their instability, these two blueprints for the employment relation have strong effects in shaping the early evolution of these firms. In particular, firms that embark with these models have significantly higher rates of replacing the founder chief executive with a non-founder as well as higher rates of completing an initial public stock offering. Some implications of these findings for future studies of imprinting and inertia in organizations are discussed

    Determinants of Managerial Intensity in the Early Years of Organizations

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    This paper examines how founding conditions shape subsequent organizational evolution— specifically, the proliferation of management and administrative jobs. Analyzing quantitative and qualitative information on a sample of young technology start-ups in California’s Silicon Valley, we examine the enduring imprint of two aspects of firms’ founding conditions: the employment blueprints espoused by founders in creating new enterprises; and the social capital that existed among key early members of the firm—their social composition and social relations. We find that the initial gender mix in start-ups and the blueprint espoused by the founder influence the extent of managerial intensity that develops over time. In particular, firms whose founders espoused a bureaucratic model from the outset subsequently grew more administratively intense than otherwise-similar companies, particularly companies whose founders had initially championed a “commitment” model. Also, firms with a higher representation of women within the first year subsequently were slower to bureaucratize than otherwise-similar firms with a predominance of males. Our analyses thus provide compelling evidence of path-dependence in the evolution of organizational structures and underscore the importance of the “logics of organizing” that founders bring to new enterprises. Implications of these results for organizational theory and research are discussed

    Henri Temianka correspondence, Gurs

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    https://digitalcommons.chapman.edu/tobin_gurs_et_al_correspondence/1000/thumbnail.jp

    3D Radiative Transfer with PHOENIX

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    Using the methods of general relativity Lindquist derived the radiative transfer equation that is correct to all orders in v/c. Mihalas developed a method of solution for the important case of monotonic velocity fields with spherically symmetry. We have developed the generalized atmosphere code PHOENIX, which in 1-D has used the framework of Mihalas to solve the radiative transfer equation (RTE) in 1-D moving flows. We describe our recent work including 3-D radiation transfer in PHOENIX and particularly including moving flows exactly using a novel affine method. We briefly discuss quantitative spectroscopy in supernovae.Comment: 13 pages, 9 figures, to appear in Recent Directions in Astrophysical Quantitative Spectroscopy and Radiation Hydrodynamics, Ed. I. Hubeny, American Institute of Physics (2009

    Presence Of A Congenitally Bicuspid Aortic Valve Among Patients Having Combined Mitral And Aortic Valve Replacement

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    Although bicuspid aortic valve occurs in an estimated 1% of adults and mitral valve prolapse in an estimated 5% of adults, occurrence of the 2 in the same patient is infrequent. During examination of operatively excised aortic and mitral valves because of dysfunction (stenosis and/or regurgitation), we encountered 16 patients who had congenitally bicuspid aortic valves associated with various types of dysfunctioning mitral valves. Eleven of the 16 patients had aortic stenosis (AS): 5 of them also had mitral stenosis, of rheumatic origin in 4 and secondary to mitral annular calcium in 1; the other 6 with aortic stenosis had pure mitral regurgitation (MR) secondary to mitral valve prolapse in 3, to ischemia in 2, and to unclear origin in 1. Of the 5 patients with pure aortic regurgitation, each also had pure mitral regurgitation: in 1 secondary to mitral valve prolapse and in 4 secondary to infective endocarditis. In conclusion, various types of mitral dysfunction severe enough to warrant mitral valve replacement occur in patients with bicuspid aortic valves. A proper search for mitral valve dysfunction in patients with bicuspid aortic valves appears warranted. (C) 2012 Elsevier Inc. All rights reserved. (Am J Cardiol 2012;109:263-271)Integrative Biolog

    Searching for Hydrogen in Type Ib Supernovae

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    We present synthetic spectral fits of the typical Type Ib SN 1999dn and the Hydrogen Rich Ib SN 2000H using the generalized non-local thermodynamic equilibrium stellar atmospheres code \phx. We fit model spectra to five epochs of SN 1999dn ranging from ten days pre-maximum light to 17 days post-maximum light and the two earliest epochs of SN 2000H available, maximum light and six days post-maximum. Our goal is to investigate the possibility of hydrogen in Type Ib Supernovae (SNe Ib), specifically a feature around 6200\AA\ which has previously been attributed to high velocity H-alpha. In earlier work on SN 1999dn we found the most plausible alternative to H-alpha to be a blend of Si II and Fe II lines which can be adjusted to fit by increasing the metallicity. Our models are simple; they assume a powerlaw density profile with radius, homologous expansion, and solar compositions. The helium core is produced by burning 4H --> He in order to conserve nucleon number. For models with hydrogen the outer skin of the model consists of a shell of solar composition. The hydrogen mass of the standard solar composition shell is M_H less than about 0.001 times the mass of the sun in SN 1999dn and M_H less than about 0.2 times the mass of the sun for SN 2000H. Our models fit the observed spectra reasonably well, successfully reproducing most features including the characteristic He I absorptions. The hydrogen feature in SN 1999dn is clear, but much more pronounced in SN 2000H. We discuss a possible evolutionary scenario that accounts for the dichotomy in the hydrogen shell mass between these two supernovae.Comment: 20 pages, 11 figures, ApJ, in pres

    Multi-layered Spectral Formation in SNe Ia Around Maximum Light

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    We use the radiative transfer code PHOENIX to study the line formation of the wavelength region 5000-7000 Angstroms. This is the region where the SNe Ia defining Si II feature occurs. This region is important since the ratio of the two nearby silicon lines has been shown to correlate with the absolute blue magnitude. We use a grid of LTE synthetic spectral models to investigate the formation of line features in the spectra of SNe Ia. By isolating the main contributors to the spectral formation we show that the ions that drive the spectral ratio are Fe III, Fe II, Si II, and S II. While the first two strongly dominate the flux transfer, the latter two form in the same physical region inside of the supernova. We also show that the naive blackbody that one would derive from a fit to the observed spectrum is far different than the true underlying continuum.Comment: 35 pages, 15 figures, ApJ (2008) 684 in pres

    A fluorophore attached to nicotinic acetylcholine receptor beta M2 detects productive binding of agonist to the alpha delta site

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    To study conformational transitions at the muscle nicotinic acetylcholine (ACh) receptor (nAChR), a rhodamine fluorophore was tethered to a Cys side chain introduced at the beta-19' position in the M2 region of the nAChR expressed in Xenopus oocytes. This procedure led to only minor changes in receptor function. During agonist application, fluorescence increased by (Delta-F/F) approximate to 10%, and the emission peak shifted to lower wavelengths, indicating a more hydrophobic environment for the fluorophore. The dose-response relations for Delta-F agreed well with those for epibatidine-induced currents, but were shifted approximate to 100-fold to the left of those for ACh-induced currents. Because (i) epibatidine binds more tightly to the alpha-gamma-binding site than to the alpha-delta site and (ii) ACh binds with reverse-site selectivity, these data suggest that Delta-F monitors an event linked to binding specifically at the alpha-delta-subunit interface. In experiments with flash-applied agonists, the earliest detectable Delta-F occurs within milliseconds, i.e., during activation. At low [ACh] (less than or equal to 10 muM), a phase of Delta-F occurs with the same time constant as desensitization, presumably monitoring an increased population of agonist-bound receptors. However, recovery from Delta-F is complete before the slowest phase of recovery from desensitization (time constant approximate to 250 s), showing that one or more desensitized states have fluorescence like that of the resting channel. That conformational transitions at the alpha-delta-binding site are not tightly coupled to channel activation suggests that sequential rather than fully concerted transitions occur during receptor gating. Thus, time-resolved fluorescence changes provide a powerful probe of nAChR conformational changes
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