5,279 research outputs found
Management Matters
No full textNew indications of managerial innovations are created and then used to show that changes in organizational technologies are an important source of economic growth. Specifically, the analysis demonstrates that, first, in response to a positive managerial technology shock, output, productivity and hours significantly increase in the short run, second, these types of innovations are as important as non-managerial ones in explaining movements in these variables at business cycle frequencies, and, third, product and process innovations promote the development of new managerial techniques.Business Cycles; Productivity; Management techniques; Technical Change
Supplemental Material, sj-pdf-1-spr-10.1177_02654075211037740 - Justify my love: Cognitive dissonance reduction among perpetrators of online and offline infidelity
No full textSupplemental Material, sj-pdf-1-spr-10.1177_02654075211037740 for Justify my love: Cognitive dissonance reduction among perpetrators of online and offline infidelity by Cassandra Alexopoulos in Journal of Social and Personal Relationships</p
On the question of the calculation of migration volumes in ionic crystals
No full textThe migration volume vm consists of two contributions vms= - T(∂sm/∂P)|T and vhm = (∂hm/∂P)|T where ∂m, hm denote the migration entropy and enthalpy. By analysing the recent experimental data of Andeen, Hayden and Fontanella (1980) on SrF2 + Er+3, obtained by dielectric-loss techniques under various pressures, the term vsm is found to be a considerable contribution t o vm. At 330 K the ratio|vsm|vhm is 23%. Further the compressibility ∼m of the migration volume is found to exceed the bulk compressibility K by one order of magnitude. The application of a recent macroscopic model proposed by Varotsos and Alexopoulos (1978) not only explains that ∼m is appreciably larger than but it also leads t o a value of vsm/vhm appreciably different than zero. The common disagreement between the ‘static lattice’ calculations of vm and experiments lies in the fact that the contribution cannot be neglected. © 1980 Taylor &amp; Francis Group, LLC
Extracellular matrix associated with human luteininzing granulosa cells
No full textHuman granulosa cells (GC), prepared from follicular aspirates using a non-enzymic method, were maintained on chamber slides in a defined medium without additional attachment factors. In this system, GC clustered to a limited extend and attached only loosely to the substream necessitating medium replacement through repeated partial changes to avoid cell loss. Cell size and progesterone production increased consistently with continuing luteinization. These processes were associated with maintenance and deposition of the endogenous extracellular matrix components heparan sulphate proteoglycan and laminin (α2, β1, γ1 subunits) as shown by both Western blotting and immunohistochemistry. Collagen IV seemed to be present between freshly prepared GC and was maintained in culture. The addition of either epidermal growth factor (EGF) or basic fibroblast growth factor (bFGF) into the culture medium did not reveal any marked effect on deposition of laminin components during culture. Release of cell clusters, particularly in the absence of gonadotrophin, was noted during the later stages of culture, constituting the so-called 'lift off' phenomenon. This has been correlated with an increasing concentration of matrix metalloproteinases (MMP-2) in the culture medium during the culture period. To conclude, luteinization and maintenance of the GC-derived layer of the corpus luteum is likely to involve deposition and conservation of pericellular extracellular matrix components, actively synthesized by the GC themselves and controlled by the presence of gonadotrophin.</p
Prediction of the compressibility of mixed alkali halides
No full textA model has been recently proposed by Varotsos and Alexopoulos which permits the calculation of the compressibility kd of the volume of a defect from elastic properties of the surrounding lattice. This expression for kd in conjunction with the Born model, as modified by Smith and coworkers, permits the determination of the compressibility and its pressure dependence of an alkali halide mixed crystal. The application of the proposed method to the system KCl-KBr shows excellent agreement between the predicted and the experimental values obtained by Slagle and McKinstry and recently by Cain. © 1980
Stratigraphy of Aptian-Cenomanian carbonate sequence of the Tripolitza platform in central Crete (Greece) : evidence of subaerial exposures
No full textZambetakis-Lekkas Alexandra, Pomoni-Papaioannou Fotini, Alexopoulos Apostolos. Stratigraphy of Aptian-Cenomanian carbonate sequence of the Tripolitza platform in central Crete (Greece) : evidence of subaerial exposures. In: Documents des Laboratoires de Géologie, Lyon, n°156, 2002. STRATI 2002. 3ème congrès français de stratigraphie. Lyon, 8-10 juillet 2002. p. 240
Bayesian prediction of jumps in large panels of time series data
No full textWe take a new look at the problem of disentangling the volatility and jumps processes of daily stock returns. We first provide a computational framework for the univariate stochastic volatility model with Poisson-driven jumps that offers a competitive inference alternative to the existing tools. This methodology is then extended to a large set of stocks for which we assume that their unobserved jump intensities co-evolve in time through a dynamic factor model. To evaluate the proposed modelling approach we conduct out-of-sample forecasts and we compare the posterior predictive distributions obtained from the different models. We provide evidence that joint modelling of jumps improves the predictive ability of the stochastic volatility models
Effect of corrosion-induced hydrogen embrittlement and its degradation impact on tensile properties and fracture toughness of (Al-Cu-Mg) 2024 alloy
No full textAbstractIn the present work, the effect of artificial ageing of AA2024-T3 on the tensile mechanical properties and fracture toughness degradation due to corrosion exposure will be investigated. Tensile and fracture toughness specimens were artificially aged to tempers that correspond to Under-Ageing (UA), Peak-Ageing (PA) and Over-Ageing (OA) conditions and then were subsequently exposed to exfoliation corrosion environment. The corrosion exposure time was selected to be the least possible according to the experimental work of Alexopoulos et al. (2016) so as to avoid the formation of large surface pits, trying to simulate the hydrogen embrittlement degradation only. The mechanical test results show that minimum corrosion-induced decrease in elongation at fracture was achieved for the peak-ageing condition, while maximum was noticed at the under-ageing and over-ageing conditions. Yield stress decrease due to corrosion is less sensitive to tempering; fracture toughness decrease was sensitive to ageing heat treatment thus proving that the S΄ particles play a significant role on the corrosion-induced degradation
Bayesian forecasting of mortality rates by using latent Gaussian models
No full textWe provide forecasts for mortality rates by using two different approaches. First we employ dynamic non-linear logistic models based on the Heligman–Pollard formula. Second, we assume that the dynamics of the mortality rates can be modelled through a Gaussian Markov random field. We use efficient Bayesian methods to estimate the parameters and the latent states of the models proposed. Both methodologies are tested with past data and are used to forecast mortality rates both for large (UK and Wales) and small (New Zealand) populations up to 21 years ahead. We demonstrate that predictions for individual survivor functions and other posterior summaries of demographic and actuarial interest are readily obtained. Our results are compared with other competing forecasting methods.</p
The Liturgical Book of the Oktoechos. Function, Forms, and Manuscript Tradition
No full textThis chapter offers a detailed investigation into the liturgical book known as the Oktoechos within the Byzantine tradition, focusing on its function, structure, and manuscript history. The Author clarifies the multiple meanings of the term "oktoechos" in Byzantine sources, distinguishing between the musical eight-mode system, the weekly liturgical cycle, and the book itself. The study explores the evolution of the Oktoechos from its early roots in the Jerusalem liturgical tradition, particularly through Georgian and Greek sources such as the Old and New Tropologion. The work highlights the interplay between the Oktoechos and other liturgical books like the Menaion, Triodion, and Pentekostarion, and traces the contribution of major hymnographers including John of Damascus and Andrew of Crete. Special attention is given to terminological ambiguities, manuscript variants, and regional adaptations. Overall, the chapter presents a nuanced reconstruction of the development and standardization of this central Byzantine liturgical book
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