3,285 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
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
Recommended from our members
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
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
Recommended from our members
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
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
Gyrofluid simulations of collisionless reconnection in the presence of diamagnetic effects
The effects of the ion Larmor radius on magnetic reconnection are
investigated by means of numerical simulations, with a Hamiltonian gyrofluid
model. In the linear regime, it is found that ion diamagnetic effects decrease
the growth rate of the dominant mode. Increasing ion temperature tends to make
the magnetic islands propagate in the ion diamagnetic drift direction. In the
nonlinear regime, diamagnetic effects reduce the final width of the island.
Unlike the electron density, the guiding center density does not tend to
distribute along separatrices and at high ion temperature, the electrostatic
potential exhibits the superposition of a small scale structure, related to the
electron density, and a large scale structure, related to the ion
guiding-center density
Gyrofluid simulations of collisionless reconnection in the presence of diamagnetic effects
The effects of the ion Larmor radius on magnetic reconnection are
investigated by means of numerical simulations, with a Hamiltonian gyrofluid
model. In the linear regime, it is found that ion diamagnetic effects decrease
the growth rate of the dominant mode. Increasing ion temperature tends to make
the magnetic islands propagate in the ion diamagnetic drift direction. In the
nonlinear regime, diamagnetic effects reduce the final width of the island.
Unlike the electron density, the guiding center density does not tend to
distribute along separatrices and at high ion temperature, the electrostatic
potential exhibits the superposition of a small scale structure, related to the
electron density, and a large scale structure, related to the ion
guiding-center density
Gyrofluid simulations of collisionless reconnection in the presence of diamagnetic effects
The effects of the ion Larmor radius on magnetic reconnection are
investigated by means of numerical simulations, with a Hamiltonian gyrofluid
model. In the linear regime, it is found that ion diamagnetic effects decrease
the growth rate of the dominant mode. Increasing ion temperature tends to make
the magnetic islands propagate in the ion diamagnetic drift direction. In the
nonlinear regime, diamagnetic effects reduce the final width of the island.
Unlike the electron density, the guiding center density does not tend to
distribute along separatrices and at high ion temperature, the electrostatic
potential exhibits the superposition of a small scale structure, related to the
electron density, and a large scale structure, related to the ion
guiding-center density
Muon Catalyzed Fusion in 3 K Solid Deuterium
Muon catalyzed fusion in deuterium has traditionally been studied in gaseous
and liquid targets. The TRIUMF solid-hydrogen-layer target system has been used
to study the fusion reaction rates in the solid phase of D_2 at a target
temperature of 3 K. Products of two distinct branches of the reaction were
observed; neutrons by a liquid organic scintillator, and protons by a silicon
detector located inside the target system. The effective molecular formation
rate from the upper hyperfine state of and the hyperfine transition
rate have been measured: , and .
The molecular formation rate is consistent with other recent measurements, but
not with the theory for isolated molecules. The discrepancy may be due to
incomplete thermalization, an effect which was investigated by Monte Carlo
calculations. Information on branching ratio parameters for the s and p wave
d+d nuclear interaction has been extracted.Comment: 19 pages, 11 figures, submitted to PRA Feb 20, 199
- …
