2,598 research outputs found

    China, India and Russia: economic reforms, structural change and regional disparities

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    This paper studies the different patterns of growth of China, India and Russia by exploring and comparing the processes of reforms that have generated and accompanied their high and sustained rates of growth. Focusing on the sector transformations involved into the three economies, we show that the growth strategies implemented present specific characteristics in terms of gradualism and policy choices. We analyze the effects of economic growth on regional income disparities and to what extent the recent increase in prosperity has been homogeneously distributed within the three giants. Making use of Theil's T statistics and transition probability matrices, our findings reveal that income disparities within the Indian states and Chinese provinces have increased and, more in particular, landlocked and rural areas are in general still far from reducing the income gap from coastal and richest regions. In the case of Russia, the great divide is fuelled by the presence of hydrocarbons resources, which tend to be concentrated in the West Siberia

    Computing Volume Bounds of Inclusions by EIT Measurements

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    The size estimates approach for Electrical Impedance Tomography (EIT) allows for estimating the size (area or volume) of an unknown inclusion in an electrical conductor by means of one pair of boundary measurements of voltage and current. In this paper we show by numerical simulations how to obtain such bounds for practical application of the method. The computations are carried out both in a 2D and a 3D setting.Comment: 20 pages with figure

    Multiscale optical flow computation from the monogenic signal

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    National audienceWe have developed an algorithm for the estimation of cardiac motion from medical images. The algorithm exploits monogenic signal theory, recently introduced as an N-dimensional generalization of the analytic signal. The displacement is computed locally by assuming the conservation of the monogenic phase over time. A local affine displacement model replaces the standard translation model to account for more complex motions as contraction/expansion and shear. A coarse-to-fine B-spline scheme allows a robust and effective computation of the models parameters and a pyramidal refinement scheme helps handle large motions. Robustness against noise is increased by replacing the standard pointwise computation of the monogenic orientation with a more robust least-squares orientation estimate. This paper reviews the results obtained on simulated cardiac images from different modalities, namely 2D and 3D cardiac ultrasound and tagged magnetic resonance. We also show how the proposed algorithm represents a valuable alternative to state-of-the-art algorithms in the respective fields

    Operator Formulation of q-Deformed Dual String Model

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    We present an operator formulation of the q-deformed dual string model amplitude using an infinite set of q-harmonic oscillators. The formalism attains the crossing symmetry and factorization and allows to express the general n-point function as a factorized product of vertices and propagators.Comment: 6pages, Late

    Characterization of ellipses as uniformly dense sets with respect to a family of convex bodies

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    Let K \subset R^N be a convex body containing the origin. A measurable set G \subset R^N with positive Lebesgue measure is said to be uniformly K-dense if, for any fixed r > 0, the measure of G \cap (x + rK) is constant when x varies on the boundary of G (here, x + rK denotes a translation of a dilation of K). We first prove that G must always be strictly convex and at least C1,1-regular; also, if K is centrally symmetric, K must be strictly convex, C1,1-regular and such that K = G - G up to homotheties; this implies in turn that G must be C2,1- regular. Then for N = 2, we prove that G is uniformly K-dense if and only if K and G are homothetic to the same ellipse. This result was already proven by Amar, Berrone and Gianni in [3]. However, our proof removes their regularity assumptions on K and G and, more importantly, it is susceptible to be generalized to higher dimension since, by the use of Minkowski's inequality and an affine inequality, avoids the delicate computations of the higher-order terms in the Taylor expansion near r = 0 for the measure of G\cap(x+rK) (needed in [3])

    [A cohort study on mortality and morbidity in the area of Taranto, Southern Italy].

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    Introduction: the area of Taranto has been investigated in several environmental and epidemiological studies due to the presence of many industrial plants and shipyards. Results from many studies showed excesses of mortality and cancer incidence for the entire city of Taranto, but there are no studies for different geographical areas of the city that take into account the important confounding effect of socioeconomic position. Objective: to assess mortality and hospitalization rates of residents in Taranto, Statte and Massafra through a cohort study, with a particular focus on residents in the districts closest to the industrial complex, taking into account the socioeconomic position. Methods: a cohort of residents during the period 1998-2010 was enrolled. Individual follow-up for assessment of vital status at 31.01.2010 was performed using municipality data. The census-tract socioeconomic position level and the district of residence were assigned to each participant, on the basis of the geocoded addresses at the beginning of the follow-up. Standardized cause specific mortality/morbidity rates, adjusted for age, were calculated by gender and districts of residence. Mortality and morbidity Hazard Ratios (HR, CI95%) were calculated by districts and socioeconomic position using Cox models. All models were adjusted for age and calendar period, and were done separately for men and women. Results: 321.356 people were enrolled in the cohort (48.9% males). Mortality/morbidity risks for natural cause, cancers, cardiovascular and respiratory diseases were found to be higher in low socioeconomic position groups compared to high ones. The analyses by districts have shown several excess mortality/morbidity risks for residents in Tamburi (Tamburi, Isola, Porta Napoli and Lido Azzurro), Borgo, Paolo VI and the municipality of Statte. Conclusions: The results of this study showed a significant relationship between socioeconomic position and health status of people resident in Taranto. People living in the districts closest to the industrial zone have higher mortality/morbidity levels compared to the rest of the area also taking into account the socioeconomic position

    Cerebral plasticity in acute vestibular deficit

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    The aim of this study was to analyze the effect of acute vestibular deficit on the cerebral cortex and its correlation with clinical signs and symptoms. Eight right-handed patients affected by vestibular neuritis, a purely peripheral vestibular lesion, underwent two brain single photon emission computed tomography (SPECT) in 1 month. The first SPECT analysis revealed reduced blood flow in the temporal frontal area of the right hemisphere in seven of eight patients, independent of the right/left location of the lesion. The alteration was present always in the right, non-dominant hemisphere and was reversible in some patients 1 month after the onset, together with attenuation of signs and symptoms. It may be hypothesized that the transient reduction of cortical blood flow and subsequently of cortical activity in the non-dominant hemisphere, also the expression of cerebral plasticity, may serve as a defense mechanism aimed to attenuate the vertigo symptom

    The stability for the Cauchy problem for elliptic equations

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    We discuss the ill-posed Cauchy problem for elliptic equations, which is pervasive in inverse boundary value problems modeled by elliptic equations. We provide essentially optimal stability results, in wide generality and under substantially minimal assumptions. As a general scheme in our arguments, we show that all such stability results can be derived by the use of a single building brick, the three-spheres inequality.Comment: 57 pages, review articl

    Cortical metabolic arrangement during olfactory processing:proposal for a 18F-FDG PET/CT methodological approach

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    The aim of this article is to investigate the cortical metabolic arrangements in olfactory processing by using 18F fluorodeoxyglucose (FDG) positron emission tomography/computed tomography. Twenty-six normosmic individuals (14 women and 12 men; mean age 46.710 years) were exposed to a neutral olfactory condition (NC) and, after 1 month, to a pure olfactory condition (OC) in a relatively ecological environment, that is, outside the scanner. All the subjects were injected with 185-210 megabecquerel of 18F FDG during both stimulations. Statistical parametric mapping version 2 was used in order to assess differences between NC and OC. As a result, we found a significant higher glucose consumption during OC in the cuneus, lingual, and parahippocampal gyri, mainly in the left hemisphere. During NC, our results show a relative higher glucose metabolism in the left superior, inferior, middle, medial frontal, and orbital gyri as well as in the anterior cingulate cortex. The present investigation, performed with a widely available functional imaging clinical tool, may help to better understand the neural responses associated to olfactory processing in healthy individuals and in patients with olfactory disorders by acquiring data in an ecologic, noise-free, and resting condition in which possible cerebral activations related to unwanted attentional processes might be avoided

    Exponential instability in the fractional Calder\'on problem

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    In this note we prove the exponential instability of the fractional Calder\'on problem and thus prove the optimality of the logarithmic stability estimate from \cite{RS17}. In order to infer this result, we follow the strategy introduced by Mandache in \cite{M01} for the standard Calder\'on problem. Here we exploit a close relation between the fractional Calder\'on problem and the classical Poisson operator. Moreover, using the construction of a suitable orthonormal basis, we also prove (almost) optimality of the Runge approximation result for the fractional Laplacian, which was derived in \cite{RS17}. Finally, in one dimension, we show a close relation between the fractional Calder\'on problem and the truncated Hilbert transform.Comment: 17 page
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