2,434 research outputs found
Histochemical data on the skin mucous cells during the development of the trout [Translation from: Bollettino della Societa Italiana di Biologia Sperimentale 45, 1273-1276, 1969]
In the skin of Salmo irideus the production of mucus is due to one type of cell specialized as a mucus cell. The histochemical research presented in this paper describes the mucous cells of Salmo irideus and demonstrates observable variation in such cells during the fish's development
Influence of higher-order harmonics on the saturation of the tearing mode
The nonlinear saturation of the tearing mode is revisited in slab geometry by
taking into account higher-order harmonics in the outer solution. The general
formalism for tackling this problem in the case of a vanishing current gradient
at the resonant surface is derived. It is shown that, although the higher-order
harmonics lead to corrections in the final saturation equation, they are of
higher order in the perturbation parameter, which provides a formal proof that
the standard one-harmonic approach is asymptotically correct.Comment: Accepted to Plasma Physics and Controlled Fusio
Shake me the money!
During a natural disaster, the negative supply shock due to the destruction of productive capacity is counteracted by a positive demand shock due to public grants for assistance and reconstruction positing an identification issue in empirical work. Focusing on the 2009 'Aquilano' earthquake in Italy as a case study, we take advantage of quantified measure of damages for 75,424 buildings to estimate the negative supply shock and of a law issued to allocate reconstruction grants, which resulted in a sharp, exogenous discontinuity in transfers and output behavior across neighboring municipalities to estimate the positive demand shock. Diff-in-diff analysis suggests that local output multipliers of reconstruction grants (net of marginal tax rebates) are below unity. Yet the size of the grants act as a public insurance scheme, preventing a fall in output
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The Impact of Earthquakes on Economic Activity: Evidence from Italy
Although earthquakes are large idiosyncratic shocks for affected regions, little is known of their impact on economic activity. Seismic events are rare, the data is crude (the Richter scale measures the magnitude but says nothing of the associated damages) and counterfactuals are often entirely absent. We suggest an innovative identification strategy to address these issues based on the so-called ’Mercalli scale’ ranks - a geophysical methodology devised to gauge seismic damages relying on a newly compiled dataset following 95 Italian provinces from 1986 to 2011 (including 22 seismic episodes) offering an ideal ground for identification. Also, we carry out counterfactuals taking advantage of ex ante identical neighboring provinces that only differ ex post in terms of damages. Contrary to conventional views, we find that the impact of seismic events on output is negligible (or even positive) including after the most devastating events
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Reconstruction multipliers
A law issued to allocate reconstruction grants following the 2009 "Aquilano" earthquake has resulted in a large and unanticipated discontinuity across municipalities with comparable damages. Using diff-in-diff analysis we estimate the "local spending" and the "local tax" multipliers--according to the composition of the stimulus--controlling for the negative supply shock generated by the event. The stimulus prevented a fall in economic activity and the multiplicative effects of tax cuts are estimated much higher than those of spending. Our results underline the importance of countercyclical fiscal interventions and suggest the most effective composition of such a stimulus
Reconstruction multipliers
A law issued to allocate reconstruction grants following the 2009 "Aquilano" earthquake has resulted in a large and unanticipated discontinuity across municipalities with comparable damages. Using diff-in-diff analysis we estimate the "local spending" and the "local tax" multipliers--according to the composition of the stimulus--controlling for the negative supply shock generated by the event. The stimulus prevented a fall in economic activity and the multiplicative effects of tax cuts are estimated much higher than those of spending. Our results underline the importance of countercyclical fiscal interventions and suggest the most effective composition of such a stimulus
Analytic equilibrium of "straight tokamak" plasma bounded by a magnetic separatrix
Theoretical and experimental considerations suggest that axisymmetric perturbations that are resonant at the X-point(s) of a magnetic divertor separatrix may play a role in the understanding of Edge Localized Modes in tokamak experiments and their active control via so-called vertical kicks. With this motivation in mind, the first step in the development of an analytical model for resistive axisymmetric X-point modes is presented, i.e., finding an adequate, but at the same time relatively simple analytical magnetohydrodynamic equilibrium for a plasma column with a noncircular cross section bound by a magnetic separatrix. An early example is Gajewski's equilibrium solution [R. Gajewski, Phys. Fluids 15, 70 (1972)], which, however, has the shortcoming that infinite external currents placed at an infinite distance from the X-points produce the elliptical elongation of the plasma column. In this article, Gajewski's solution is extended to the case where external currents are located at a finite distance from the boundary of the plasma current density and the latter is distributed uniformly over a domain bound by a nearly elliptical magnetic flux surface
Analytic equilibrium of elongated plasmas bounded by a magnetic separatrix and the problem of resistive axisymmetric X-point modes
Theoretical and experimental considerations suggest that axisymmetric perturbations that are resonant at the X-point(s) of a magnetic divertor separatrix may play a role for the understanding of ELMs in tokamaks and their active control via so-called vertical kicks. The first step in the development of an analytic model for resistive axisymmetric X-point modes is presented, i.e., finding an adequate and relatively simple analytic MHD equilibrium for a plasma column with noncircular cross section bounded by a magnetic separatrix
Revenue vs expenditure based fiscal consolidation: the pass-through from federal cuts to local taxes
A growing literature emphasizes that the output effect of fiscal consolidation hinges on its composition, as the choice of increasing revenues vs cutting expenditure is not neutral. Existing studies, however, underscore the role of local governments in a federal setting. Indeed, transfer cuts at the central level might translate into higher local taxes, changing the effective composition of the fiscal adjustment. We evaluate this transmission mechanism in Italy, where municipalities below the threshold of 5,000 inhabitants were exempted from (large) transfer cuts in 2012. This allows us to implement a difference-in-discontinuities design in order to estimate the causal impact of transfer cuts on the composition of fiscal adjustment, also because tight fiscal rules impose a balanced budget on Italian municipalities. We find a pass-through mechanism by which local governments react to the contraction of intergovernmental grants by mainly increasing taxes rather than reducing spending. From a political economy perspective, this revenue based fiscal consolidation is driven by local governments with low electoral competition and low party fragmentation
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