2,058 research outputs found
Sub-national Differentiation and the Role of the Firm in Optimal International Pricing
We illuminate the relationship between optimal firm pricing and optimal trade policy by exploring a generalized model that accommodates product differentiation at both the national and sub-national (firm) levels. We assume monopolistic competition in the differentiated products at the sub-national level. When the national and sub-national substitution elasticities are similar we find little opportunity for small countries to improve their terms of trade through trade distortions, because firms play an important preemptive role in optimally pricing unique varieties. We contrast this with standard applications of perfect-competition Armington models, which exhibit high optimal tariffs--even for relatively small countries.
A Discussion on Armington Trade Substitution Elasticities
Applied partial and general equilibrium models used to examine trade policy are almost universally sensitive to trade elasticities. Indeed, the Armington elasticity, the degree of substitution between domestic and imported goods, is a key behavioral parameter that drives the quantitative, and sometimes the qualitative, results that policymakers use. While standard transparent approaches to econometric estimation of these elasticities have been offered for the last 30 years, the estimates are viewed as too small by many trade economists. A few robust findings emerge from the econometric literature: (1) more disaggregate analyses find higher elasticities, (2) long-run estimates are higher than short-run estimates, and (3) time series analyses generally find lower elasticities relative to cross-sectional studies. We offer simulation results to illustrate the sensitivity of general equilibrium models to Armington elasticites. We conclude with remarks on the current challenges that remain in determining these important parameters.International Relations/Trade,
Services liberalization in preferential trade arrangements : the case of Kenya
Given the growing importance of commitments to foreign investors in services in regional trade agreements, it is important to develop applied general equilibrium models to assess the impacts of liberalization of barriers to multinational service providers. This paper develops a 55 sector applied general equilibrium model of Kenya with foreign direct investment and Dixit-Stiglitz productivity effects from additional varieties of imperfectly competitive goods or services, and uses the model to assess its regional and multilateral trade options, focusing on commitments to foreign investors in services. To assess the sensitivity of the results to parameter values, the model is executed 30,000 times, and results are reported as confidence intervals of the sample distributions. The analysis reveals that a 50 percent preferential reduction in the ad valorem equivalents of barriers in all business services by Kenya with its African partners would be somewhat beneficial for Kenya. If a preferential agreement with African partners is combined with an agreement with the European Union, the gains would more than triple the gains of an Africa only agreement. Multilateral reduction of services barriers, however, would yield gains about 12 times the gains of an agreement with the Africa region alone. These results suggest that preferential liberalization in the region is a valuable first step, but wider liberalization, with larger partners and liberal rules of origin or multilaterally, will yield much larger gains due to providing access to a much wider set of services providers. The largest gains would come from domestic regulatory reform in services, as this would almost triple the gains of multilateral liberalization.Economic Theory&Research,Emerging Markets,Public Sector Corruption&Anticorruption Measures,Transport Economics Policy&Planning,Free Trade
A Discussion on Armington Trade Substitution Elasticities
Applied partial and general equilibrium models used to examine trade policy are almost universally sensitive to trade elasticities. Indeed, the Armington elasticity, the degree of substitution between domestic and imported goods, is a key behavioral parameter that drives the quantitative, and sometimes the qualitative, results that policymakers use. While standard transparent approaches to econometric estimation of these elasticities have been offered for the last 30 years, the estimates are viewed as too small by many trade economists. A few robust findings emerge from the econometric literature: (1) more disaggregate analyses find higher elasticities, (2) long-run estimates are higher than short-run estimates, and (3) time series analyses generally find lower elasticities relative to cross-sectional studies. We offer simulation results to illustrate the sensitivity of general equilibrium models to Armington elasticites. We conclude with remarks on the current challenges that remain in determining these important parameters.Computable general equilibrium; International Trade; Armington; elasticity
Genetic contribution in sporadic thoracic aortic aneurysm? Emerging evidence of genetic variants related to TLR-4-mediated signaling pathway as risk determinants.
Sporadic thoracic aortic aneurysms (TAA) and dissections are one of the major causes of morbidity and mortality worldwide, especially in those older than 65 years. The presentation of TAA is varied and often silent. Thus, sporadic TAA detection is often fortuitous, with identification occurring during a routine physical examination or during an unrelated medical evaluation. Once suspected, confirmation by imaging clinical approaches is needed to allow the choose of the unique treatments for TAA, namely the surgery procedures, including elective surgery or endovascular repair before the onset of catastrophic and fatal complications, such as dissection or rupture. At present, there are no biomarkers available to identify TAAs before visible symptoms. However, recent progresses in understanding of molecular and cellular mechanisms involved in the patho-physiology of sporadic TAA are suggesting different molecular pathways and their genetic variants as potential biomarkers, which might be applied into TAA clinical practice in the near future. Here, we report literature evidence on some disease pathways and their genetic variants on TAA susceptibility and compliances, and their translation as promising TAA preventive and prognostic biomarkers and targets for new personalized therapeutic treatments
UmanitĂ ed integritĂ del soldato potenziato: alcune riflessioni di bioetica militare
The article examines the moral questions that arise from the military use of enhancement technologies and claims that emerging biotechnologies can help improve the attitudes and capabilities of the soldiers without jeopardizing their integrity and humanity. Even if the military use of enhancement technologies is considered ethically justifiable, our conclusion is that soldiers should ever be compelled to take drugs or receive biotechnological treatments they object to
Accuratezza predittiva di modelli ad elementi finiti subject-specific del femore umano in condizione di caduta laterale: valutazione tramite confronto con misure sperimentali
La possibilità di determinare il campo delle sollecitazioni meccaniche indotte nelle ossa umane dalle attività fisiologiche è un fattore di grande importanza sia nella ricerca scientifica che nella pratica clinica, per permettere di effettuare scelte cliniche più efficaci, sia dal punto di vista diagnostico, che del trattamento.
L'unico modo per poter avere una stima delle sollecitazioni meccaniche sulle ossa in vivo è mediante una modellazione agli elementi finiti subject-specific.
Lo scopo del presente lavoro di tesi è stato quello di validare le predizioni degli strain in campo elastico e a rottura di modelli ad elementi finiti subject-specific per la predizione del rischio di frattura nella porzione prossimale di femori umani, mediante confronto con misure sperimentali in vitro.
Il lavoro ha previsto dunque uno studio di validazione combinato numerico-sperimentale e grazie all’utilizzo di modelli subject-specific agli elementi finiti, in grado di predire accuratamente gli strain, è stato applicato un criterio di rottura basato sui massimi strain principali abile ad identificare le caratteristiche di frattura dell’osso.
Il lavoro ha utilizzato i dati sperimentali relativi ad 11 femori di cadavere testati in campo elastico in configurazioni sia fisiologiche (Single leg stance) che parafisiologiche (Sidefall) e infine testati a rottura nello scenario di carico, clinicamente rilevante, della caduta laterale.
L’importanza e la generalità dei risultati ottenuti risiede innanzitutto in un rappresentativo numero di femori utilizzati per lo studio, nel grande numero di estensimetri utilizzati, molti dei quali concentrati nella porzione più prossimale del femore, nonché nei molti scenari di carico considerati che hanno permesso di avere una grande quantità di dati numerici di deformazione.
Questo lavoro ha permesso di ottenere dei risultati importanti relativamente alla capacità di questi modelli di predire i livelli di rischio di frattura nel femore prossimale. Ciò è necessario poiché un requisito preliminare fondamentale per future applicazioni cliniche è una validazione in vitro delle predizioni dei modelli FE.
The ability to determine the range of the mechanical stresses induced by the physiological activities in human bone is a factor of great importance both in scientific research or clinical practice, to allow either clinical choices most effective, both from the diagnostic point of view, that of the treatment.
The only way to have an estimate of the mechanical stress on bone in vivo using a finite element modeling subject-specific.
The purpose of this thesis was to validate the predictions of the strain in the elastic and fracture of finite element models for predicting subject-specific risk of fracture in the proximal portion of human femurs, by comparison with experimental measurements in vitro.
The work has thus provided a validation study combined experimental and numerical models through the use of subject-specific finite element, able to accurately predict the strain was applied as a failure criterion based on maximum principal strain able to identify the characteristics of bone fracture.
The work has used experimental data for the 11 cadaver femurs tested in the elastic field configurations in both physiological (Single leg stance) that paraphysiological (Sidefall) and finally tested to failure load scenario, clinically relevant fall off.
The importance and the generality of the results obtained resides primarily in a representative number of femurs used for the study, the large number of strain gauges used, many of which are concentrated in the portion more proximal of the femur, as well as in many load scenarios considered that allowed to have a large amount of numerical data of deformation.
This work has yielded important results regarding the ability of these models to predict levels of risk of fracture in the proximal femur. This is necessary as an essential prerequisite for future clinical applications
The current obsession of age-related diseases and the race in identifying effective treatments and preventive interventions
Tracking a light pulse through a waveguide in space and time
We present first direct observation of the propagation of a femtosecond laser pulse in space and time through a waveguide structure. With an interferometric photon scanning tunneling microscope (PSTM), the local amplitude and phase of the pulse were retrieved with high spatial, spectral and time resolution. The relative field profiles, the wave vectors and the spectra of the pulses in the TE00 and TE01 modes in the waveguide have been experimentally determined
Tra etica ed estetica: una riflessione metaetica
The thesis defended is that aesthetic experience plays an important role in moral life and that it can contribute to the perfecting of the moral character. For this reason I argue that an appropriate moral theory should offer an account of the characteristics of aesthetic experience and of the relation between ethics and aesthetics. At the end I defend the thesis that a sentimentalistic perspective is in a better position to give an account of this relation
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