4,256 research outputs found
Advertising and the evolution of market structure in the US car industry
This paper focuses on a single simple stylized fact which stands out from the post-war history of the US car industry, namely that industry concentration fell just at the same time as industry advertising expenditures rose sharply. Since both events were almost certainly caused by the entry and market penetration of (largely) foreign owned car producers, this stylized fact raises interesting questions about whether – and if so, how – advertising affects entry. We use a model of consumer switching behaviour to help interpret the facts. The model predicts a simple linear association between market and advertising shares (which we observe fairly clearly at two different levels of aggregation in the data), and provides the basis for arguing that advertising can facilitate entry, but only for finite periods of time
Grid: From EGEE to EGI and from INFN-GRID to IGI
In the last fifteen years the approach of the “computational Grid” has changed the way to use computing resources. Grid computing has raised interest
worldwide in academia, industry, and government with fast development cycles. Great efforts, huge funding and resources have been made available through national,
regional and international initiatives aiming at providing Grid infrastructures, Grid core technologies, Grid middleware and Grid applications. The Grid software layers
reflect the architecture of the services developed so far by the most important European and international projects. In this paper Grid e-Infrastructure story is given,
detailing European, Italian and international projects such as EGEE, INFN-Grid and NAREGI. In addition the sustainability issue in the long-term perspective is
described providing plans by European and Italian communities with EGI and IGI
Cytological and embryological studies in Setaria cordobensis Herrmann and Setaria leiantha Hackel (Poaceae)
SUMMARYCytogenetics and embryology of Setaria cordobensis Herrmann and S. leiantha Hackel were investigated in four populations collected from different environments in Argentina. A somatic chromosome number of 2n = 36 was confirmed for S. leiantha and reported for the first time for S. cordobensis. Bivalent pairing was regular in pollen mother cell meiosis, but abnormalities such as dyads, triads and tetrads with micronuclei or non-conventional arrangement were described with different frequencies. A high degree of similarity between the two species was found investigating megasporangium, megasporogenesis and megagametogenesis. There were major differences in ovule length and width at anthesis. Both species follow a typical Polygonum development and no indicator of apomictic processes was noted
Remarks on the analytic structure of supersymmetric effective actions
We study the effective superpotential of N=1 supersymmetric gauge theories
with a mass gap, whose analytic properties are encoded in an algebraic curve.
We propose that the degree of the curve equals the number of semiclassical
branches of the gauge theory. This is true for supersymmetric QCD with one
adjoint and polynomial superpotential, where the two sheets of its
hyperelliptic curve correspond to the gauge theory pseudoconfining and higgs
branches. We verify this proposal in the new case of supersymmetric QCD with
two adjoints and superpotential V(X)+XY^2, which is the confining phase
deformation of the D_{n+2} SCFT. This theory has three kinds of classical vacua
and its curve is cubic. Each of the three sheets of the curve corresponds to
one of the three semiclassical branches of the gauge theory. We show that one
can continuously interpolate between these branches by varying the couplings
along the moduli space.Comment: 49 pages, 3 figures, harvmac; typos correcte
Discursive chains: How prison becomes real and chains identity movements for a sex offender
Detainees enact a "self" that is faced with the prejudices and stereotypes of the crime for which that detainee was convicted. Of all inmates, sex offenders face the greatest risk of receiving social condemnation alongside their prison sentence. This empirical study worked with 32 male sex offenders over 18 years old that were housed in the "protected" unit of the Due Palazzi. The following analysis explores how these men are required to manage their "self," hetero-narrations, perception of everyday interactions in the protected unit, and conceptions about the rehabilitation path. Moreover, the detainees' view on the prison's strategic opportunities for promoting effective change in their condition and identity are also examined. Discourse analysis applied to an open answer questionnaire showed that, rather than facing the stigma assigned to them, the detainees tend to minimize the importance of storytelling and construct alternative biographies to share with other inmates. Managing narratives allows the sex offenders to distance themselves from the perceived threats of living with other detainees; however, it also prevents the re-signification of their offenses. As such, the rules of "secrecy" must be considered by both qualitative researchers who conduct studies in prisons and prison administrators who plan the housing and treatment of sex offenders
Protonation effect on the excited state behaviour of some aza-analogues of EE-distyrylbenzene
The photobehaviour of four aza-analogues ofEE-distyrylbenzene bearing the heteroatom in the two side rings [1,4-di-(2-pyridylethenyl)benzene] or in the central ring [2,5-di-(phenylethenyl)pyridine, 2,6-di(phenylethenyl)pyridine and the corresponding diene, 2,6-di(phenylbutadienyl)pyridine] has been investigated in aqueous solutions at pH 2 and 9, where the molecules are in mono-protonated and neutral forms, respectively. The type of conjugation, linear for the first two compounds and crossed for the others, is particularly important in determining the spectral and photochemical properties. The main effects of the protic solvent are a reduction of the radiative deactivation, prevalent in the corresponding hydrocarbons, and an increase of the reactive deactivation, very modest in the hydrocarbons. The increase in photoreactivity to detriment of fluorescence, observed in protic medium with respect to non-polar solvents, is drastically emphasized in acid medium where the fluorescence quantum yield decreases by an order of magnitude leading to high values of theEE→ZEphotoisomerization quantum yield. The presence of conformational isomerism (two main conformers were detected) has been observed in both basic and acid media for compounds with crossed conjugation and for the linearly conjugated 2,5 substituted pyridine. The results obtained give a picture of the different photobehaviour of the neutral and protonated species and indicate the experimental conditions to favour a specific relaxation pathway
Mission-oriented policies and the “Entrepreneurial State” at work: An agent-based exploration
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