Determinants of the income velocity of money in Portugal: 1891–1998

This paper performs a long-run time series analysis of the behaviour of the income velocity of money in Portugal between 1891 and 1998 by assessing the importance of both macroeconomic and institutional factors and looking for particularities in the Portuguese case. We estimate two cointegration vectors for the income velocity of money, macroeconomic variables and institutional variables. It is apparent that one of these vectors reflects the relationship between income velocity and macroeconomic variables, while the other reflects the relationship between income velocity and institutional variables. Moreover, a regression analysis reveals that the usual U-shaped pattern is displayed with a relatively late inflection point located around 1970, which is consistent with the Spanish case. It is further noted that this is a feature of countries with a late economic and institutional development process.info:eu-repo/semantics/publishedVersio

Synthesis of titanate nanostructures using amorphous precursor material and their adsorption/photocatalytic properties

This paper reports on a new and swift hydrothermal chemical route to prepare titanate nanostructures (TNS) avoiding the use of crystalline TiO2 as starting material. The synthesis approach uses a commercial solution of TiCl3 as titanium source to prepare an amorphous precursor, circumventing the use of hazardous chemical compounds. The influence of the reaction temperature and dwell autoclave time on the structure and morphology of the synthesised materials was studied. Homogeneous titanate nanotubes with a high length/diameter aspect ratio were synthesised at 160^{\circ}C and 24 h. A band gap of 3.06\pm0.03 eV was determined for the TNS samples prepared in these experimental conditions. This value is red shifted by 0.14 eV compared to the band gap value usually reported for the TiO2 anatase. Moreover, such samples show better adsorption capacity and photocatalytic performance on the dye rhodamine 6G (R6G) photodegradation process than TiO2 nanoparticles. A 98% reduction of the R6G concentration was achieved after 45 minutes of irradiation of a 10 ppm dye aqueous solution and 1 g/L of TNS catalyst.Comment: 29 pages, 10 figures, accepted for publication in Journal of Materials Scienc

Exchange bias in Fe/EuTe(111) bilayers

We report on the investigation of the exchange bias effect in Fe layers on EuTe(111), an antiferromagnetic semiconductor. For this ferromagnet (FM)/semiconducting antiferromagnet (AFM) exchange bias system, we have found positive and negative exchange bias effect (EB). Fresh samples exhibit positive EB, independently of the applied cooling field, indicating antiferromagnetic coupling between the FM and the AFM layers at the Fe/EuTe(111) interface. The change in EB with time, from positive EB for fresh samples to negative EB after short time,is attributed to aging effects at the Fe/EuTe interface. (c) 2007 American Institute of Physics.102

Enteric Neurospheres Are Not Specific to Neural Crest Cultures: Implications for Neural Stem Cell Therapies

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited

Performance measures for upper gastrointestinal endoscopy:A European Society of Gastrointestinal Endoscopy (ESGE) Quality Improvement Initiative

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IL-21 signaling is essential for optimal host resistance against Mycobacterium tuberculosis infection

IL-21 is produced predominantly by activated CD4(+) T cells and has pleiotropic effects on immunity via the IL-21 receptor (IL-21R), a member of the common gamma chain (gamma(c)) cytokine receptor family. We show that IL-21 signaling plays a crucial role in T cell responses during Mycobacterium tuberculosis infection by augmenting CD8(+) T cell priming, promoting T cell accumulation in the lungs, and enhancing T cell cytokine production. In the absence of IL-21 signaling, more CD4(+) and CD8(+) T cells in chronically infected mice express the T cell inhibitory molecules PD-1 and TIM-3. We correlate these immune alterations with increased susceptibility of IL-21R(-/-) mice, which have increased lung bacterial burden and earlier mortality compared to WT mice. Finally, to causally link the immune defects with host susceptibility, we use an adoptive transfer model to show that IL-21R(-/-) T cells transfer less protection than WT T cells. These results prove that IL-21 signaling has an intrinsic role in promoting the protective capacity of T cells. Thus, the net effect of IL-21 signaling is to enhance host resistance to M. tuberculosis. These data position IL-21 as a candidate biomarker of resistance to tuberculosis.This work was supported by National Institutes of Health Grants R21 AI100766, R01 AI106725, and P01 AI073748