478 research outputs found
MODELING OF SQUARE AND RECTANGULAR CONCRETE COLUMNS CONFINED BY C-FRP
No full textIn a companion paper, experimental results on C-FRP confined square and rectangular cross-section columns have been presented and indications have been gathered regarding their behavior, particularly, on how: 1) concepts and results on circular sections could be adapted to such cases, 2) scale factors, depending on column height, should be taken into account in order to extend to real-scale cases the
results obtained from small size specimens. Starting from the discussion of classical concrete failure criteria, the paper develops criteria and numerical models for the prediction of the behavior, under concentric axial load, of FRP-confined square and rectangular cross-section columns
The welfare loss from unstable inflation
No full textThe Calvo price-setting mechanism produces relative-price dispersion among firms, while the Rotemberg model is consistent with a symmetric equilibrium. Nonetheless, both models imply the same welfare costs of inflation and the same prescriptions for welfare-maximizing Central Banks. (c) 2006 Elsevier B.V. All rights reserved
Assessment di edifici in c.a. soggetti ad azione sismica: un modello semplificato di tipo adaptive push-over
No full textIn questo lavoro si propone un metodo di calcolo semplificato per l’assessment di strutture esistenti in c.a.. Il metodo consiste nella riduzione dell’edificio da analizzare ad un sistema non lineare a masse concentrate, e nella valutazione delle accelerazioni di inizio danno e di collasso attraverso una analisi push over. Si valuta, per il modello semplificato descritto, l’accuratezza di diverse tecniche di analisi pushover mettendone a confronto i risultati con i risultati di analisi dinamiche non lineari effettuate sullo stesso modello meccanico di partenza, soggetto ad accelerogrammi spettro compatibili. I risultati ottenuti sembrano indicare la maggiore affidabilità del push over adattivo, con funzione di carico definita dal solo primo modo. Emergono interessanti spunti per futuri approfondimenti, relativi alla calibrazione dello strength reduction factor, e ad una migliore definizione delle proprietà dissipative della cosiddetta substitute structure qualora si usi, per la valutazione dell’accelerazione di collasso, lo spettro di risposta in spostamento.A simplified method for the assessment of existing r.c. structures is presented. The method reduces any given building into a lumped masses MDOF system and determines the initial damage and collapse accelerations of the system by means of a pushover analysis. The work aims particularly at evaluating the accuracy of different pushover procedures, com-paring them against the results of non linear dynamic analyses performed on the same mechanical model, subjected to spectrum-compatible earthquakes. The study seems to suggest that the more reliable results are obtained by means of an adaptive pushover method, with the first modal shape assumed as displacement pattern and acceleration response spectra used in the final assessment evaluation. Moreover, some interesting suggestions for future developments emerge, such as the calibration of the strength reduction factor and of the damping properties of the so-called substitute structure, in a force and displacement-based approach respectively
Monocromatic excimer Light treatment of psoriasis
No full textB a c k g round: Various reports showed the efficacy of Narrow Band UVB (311-313
nm) and excimer laser (308 nm) in the treatment of psoriasis.
Objective: To prove the efficacy of light produced by xenon-cloride excimer at 308
nm (Monochromatic Excimer Light, MEL) in the treatment of stable forms of
localized plaque psoriasis.
Patients and methods: This study was an open trial with 152 patients affected with
stable mild to moderate plaque psoriasis (PASI score between 4 and 12) were
t reated with a weekly session of MEL A total number of 6-16 sessions was
p e rformed with a dose increase according to patient phototype and re s p o n s e .
Results: 152 patients were enrolled in the study and 149 completed the pro t o c o l .
Patients were followed up every two weeks, 57 patients for one-year and 92 patients
for 6 months. After 4 months there was complete remission in 87 patients, partial
remission in 37 and moderate improvement in 25 patients.
Conclusions: These pre l i m i n a ry results suggest that MEL can be considered as a
valid option for treatment of selected forms of localized plaque psoriasis
Monetary policy and stock-price dynamics in a DSGE framework
No full textThis paper analyzes the role of stock prices in driving monetary policy for price stability in a non-Ricardian DSGE model. It shows that the dynamics of the interest rate consistent with price stability requires a response to stock-price changes that depends on the shock driving them: a supply shock (e.g. productivity) does not require an additional, dedicated response relative to the standard Representative-Agent framework, while a demand shock does. Moreover, we show that implementing the flexible-price allocation by means of an interest-rate rule that reacts to deviations of the stock-price level from the flexible-price equilibrium incurs risks of endogenous instability that are the higher the less profitable on average equity shares. On the other hand, reacting to the stock-price growth rate is risk-free from the perspective of equilibrium determinacy, and can be beneficial from an overall real stability perspective. (C) 2011 Elsevier Inc. All rights reserved
SUMO: A (Oxidative) Stressed Protein
No full textRedox species are produced during the physiological cellular metabolism of a normal tissue. In turn, their presence is also attributed to pathological conditions including neurodegenerative diseases. Many are the molecular changes that occur during the unbalance of the redox homeostasis. Interestingly, posttranslational protein modifications (PTMs) play a remarkable role. In fact, several target proteins are modified in their activation, localization, aggregation, and expression after the cellular stress. Among PTMs, protein SUMOylation represents a very important molecular modification pathway during "oxidative stress". It has been reported that this ubiquitin-like modification is a fine sensor for redox species. Indeed, SUMOylation pathway efficiency is affected by the exposure to oxidative species in a different manner depending on the concentration and time of application. Thus, we here report updated evidence that states the role of SUMOylation in several pathological conditions, and we also outline the key involvement of c-Jun N-terminal kinase and small ubiquitin modifier pathway cross talk
Productivity shocks, stabilization policies and the dynamics of net foreign assets
No full textIn this paper we investigate the role of macroeconomic stabilization policies for the international transmission of productivity shocks and their effects on the external sector. We develop a two-country stochastic Dynamic New-Keynesian "perpetual youth" model of the business cycle with incomplete international financial markets. Our OLG structure implies stationary net foreign asset dynamics and allows for a thorough analysis of the interaction of monetary policy with non-balanced budget fiscal policy. We derive the dynamic and cyclical properties of fiscal deficit feedback rules and their implications for net foreign assets dynamics. Our results imply that the degree of "fiscal discipline", i.e. the extent to which the fiscal rule responds to debt dynamics, is crucial for the dynamics of net foreign assets. We show that under a counter-cyclical fiscal rule with low fiscal discipline temporary positive productivity shocks may result in substantial deteriorations of the Net Foreign Asset position in the medium run. This result crucially hinges on the interplay among nominal rigidities, non-balanced budget fiscal policy, and the wealth effects on consumption that are implied by our OLG structure. (C) 2012 Elsevier B.V. All rights reserved
- …
