Search results for "Inflation"
showing 10 items of 210 documents
Dynamic hyperinflation during the 6-min walk test in severely asthmatic subjects
2018
We tested the hypothesis that dynamic hyperinflation develops in severe asthmatic subjects during exercise. Changes in inspiratory capacity (IC) were measured during the 6-min walk test (6MWT) in severe asthmatic subjects compared with chronic obstructive pulmonary disease (COPD) subjects with a similar degree of bronchial obstruction. We assessed whether changes in IC were associated with changes in dyspnoea perception. 27 severe asthmatic subjects (10 males and 17 females) and 43 COPD subjects (35 males and eight females) were recruited. The two groups performed similarly in the 6MWT (p=0.90). At the end of the test, the Borg score increased significantly in both groups (mean difference: …
Radiative axion inflation
2019
Planck data robustly exclude the simple $\lambda\phi^4$ scenario for inflation. This is also the case for models of Axion Inflation in which the inflaton field is the radial part of the Peccei-Quinn complex scalar field. In this letter we show that for the KSVZ model it is possible to match the data taking into account radiative corrections to the tree level potential. After writing down the 1-loop Coleman-Weinberg potential, we show that a radiative plateau is easily generated thanks to the fact that the heavy quarks are charged under $SU(3)_c$ in order to solve the strong CP problem. We also give a numerical example for which the inflationary observables are computed and the heavy quarks …
Inflation, quantum fields, and CMB anisotropies
2009
Revert field Inflationary cosmology has proved to be the most successful at predicting the properties of the anisotropies observed in the cosmic microwave background (CMB). In this essay we show that quantum field renormalization significantly influences the generation of primordial perturbations and hence the expected measurable imprint of cosmological inflation on the CMB. However, the new predictions remain in agreement with observation, and in fact favor the simplest forms of inflation. In the near future, observations of the influence of gravitational waves from the early universe on the CMB will test our new predictions.
The airway response to deep inspirations decreases with COPD severity and is associated with airway distensibility assessed by computed tomography.
2008
In patients with mild chronic obstructive pulmonary disease (COPD), the effect of deep inspirations (DIs) to reverse methacholine-induced bronchoconstriction is largely attenuated. In this study, we tested the hypothesis that the effectiveness of DI is reduced with increasing disease severity and that this is associated with a reduction in the ability of DI to distend the airways. Fifteen subjects [Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage I–II: n = 7; GOLD stage III–IV: n = 8] underwent methacholine bronchoprovocation in the absence of DI, followed by DI. The effectiveness of DI was assessed by their ability to improve inspiratory vital capacity and forced expira…
Weighting Elementary Prices in Consumer Price Index Construction Using Spatial Autocorrelation
2013
The Consumer Price Indexes (CPI) are used in current economic systems to measure inflation. When constructing CPIs, however, official institutions have systematically overlooked the spatial dimension of elementary prices. Ignoring the fact that prices are collected at geographical locations implicitly implies considering prices as spatially independent, when in fact they are not. To solve this problem, this article proposes to weight basic price data by taking into account the spatial correlation they display. The weighted geometric and arithmetic means suggested generalize and improve the simple geometric and arithmetic means currently in use.
Sample-size calculation and reestimation for a semiparametric analysis of recurrent event data taking robust standard errors into account
2014
In some clinical trials, the repeated occurrence of the same type of event is of primary interest and the Andersen-Gill model has been proposed to analyze recurrent event data. Existing methods to determine the required sample size for an Andersen-Gill analysis rely on the strong assumption that all heterogeneity in the individuals' risk to experience events can be explained by known covariates. In practice, however, this assumption might be violated due to unknown or unmeasured covariates affecting the time to events. In these situations, the use of a robust variance estimate in calculating the test statistic is highly recommended to assure the type I error rate, but this will in turn decr…
Price convergence of peripheral European countries on the way to the EMU: A time series approach
2000
This paper examines price and inflation convergence between three European countries (Italy, Spain and the U.K.) and a European average and, alternatively, between them and Germany from the beginning of the 80's.
Imperfect information and consumer inflation expectations:evidence from microdata
2017
This paper explores which factors trigger an adjustment in consumers’ inflation expectations and looks at the implications regarding forecast errors. We find support for imperfect information models, as inflation volatility and news trigger an adjustment in expectations. Furthermore, we document that individual expectations become more accurate if they have been adjusted.
Asymptotic efficiency of the calibration estimator in a high-dimensional data setting
2022
Abstract In a finite population sampling survey, auxiliary information is commonly used to improve the Horvitz-Thompson estimators and calibration has been extensively used by national statistical agencies over the last decades for that purpose. This method enables to make estimators consistent with known totals of auxiliary variables and to reduce variance if the calibration variables are explanatory for the variable of interest. Nowadays, it is not unusual anymore to have high-dimensional auxiliary data sets and adding too much additional calibration variables may increase the variance of calibration estimators. We study in this paper the asymptotic efficiency of the calibration estimator…
Noncanonical approaches to inflation
2019
El paradigma inflacionario provee al Modelo Cosmológico Estándar de un mecanismo que fácilmente resuelve los problemas del horizonte y la planicie y, al mismo tiempo, produce las semillas primordiales que se dieron lugar a las estructuras que hoy vemos en el cielo. Independientemente de la naturaleza precisa del mecanismo, la inflación cosmológica consiste en una etapa de aceleración durante el universo primitivo que sucedió momentos después del big bang. En esta Tesis, cubrimos aproximaciones fenomenológicas y teóricas sobre el estudio de la inflación: desde parametrizaciones independientes de modelos a modificaciones de las leyes de gravedad. Está dividida en cuatro partes. La primera, co…