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New methodology to measure the dynamics of ocular wave front aberrations during small amplitude changes of accommodation
We present a methodology to measure the systematic changes of aberrations induced by small changes in amplitude of accommodation. We use a method similar the one used in electrophysiology, where a periodic stimulus is presented to the eye and many periods (epochs) of the stimulus are averaged. Using this technique we have measured changes in higher order aberrations from 0.006ÎĽm to 0.02ÎĽm and correlated them with amplitude changes of accommodation as small as 0.14D. These small changes would have been undetectable without epoch averaging. The correlation coefficients of Zernike terms with defocus were calculated, demonstrating higher values of correlation for epoch averaging. The accurate monitoring of defocus at the start of the accommodation response has shown some interesting trends that may be related with the mechanisms behind accommodation
Post-EMS exchange risk trends: A comparative perspective between Euro, British Pound and Japanese Yen excess returns against US Dollar
This paper studies the exchange rate risk of Euro, Pound and Yen against US Dollar before and after the EMU. The key question is to analyse the impact of the Euro to exchange rate risks. The risk is measured by estimating risk price coefficient (RPC) from an excess return equation. A conditional heteroskedastic variance model with time-varying mean is estimated for this purpose. Recursive estimates are used to examine the evolution of the parameters and to find out time-varying risk premia. Results show that after a period of adaptation following the introduction of the Euro, the Euro/US Dollar RPC decreased.Exchange rate risk, GARCH-M, risk-price, times series, recursive estimation
An unpublished interview with Paulo Freire: radical pedagogy & social transformation
Pulling together the inedited works by Paulo Freire in the XXI century shows us how his works are up-to-date with current issues in the field. Most of his works have been disseminated all over the World, as those of the greatest educator of all times; however, his simplicity and outspoken voice is unique and cannot be reproduce in a simple manner. This is possibly why many writers use his citations, instead of paraphrasing his writings. Therefore, this paper represents another attempt to focus on his own voice and perspective on some of the questions raised by students three decades ago, that had never reach a broad audience but are nevertheless still in the minds of many students who are today interested in his work. The paper presents a short unpublished interview with Freire in 1988, when he talks about theoretical affiliation, critiques and the objectives of his works. In a conversation format the interview is a re-encounter between Paulo Freire and his former student Carmen de Mattos
Employment conditions and health inequalities.
Final Report to the WHO Commission on Social Determinants of Health (CSDH), Geneva
Reactivity of tri(2-furyl)phosphine (Pfu\u3csub\u3e3\u3c/sub\u3e) with [Mn\u3csub\u3e2\u3c/sub\u3e(CO)\u3csub\u3e10–\u3cem\u3en\u3c/em\u3e\u3c/sub\u3e(NCMe)\u3csub\u3e\u3cem\u3en\u3c/em\u3e\u3c/sub\u3e] (\u3cem\u3en\u3c/em\u3e = 0–2): X-ray Structure of \u3cem\u3emer\u3c/em\u3e-[Mn(CO)\u3csub\u3e3\u3c/sub\u3e(η\u3csup\u3e1\u3c/sup\u3e-C\u3csub\u3e4\u3c/sub\u3eH\u3csub\u3e3\u3c/sub\u3eO)(Pfu\u3csub\u3e3\u3c/sub\u3e)\u3csub\u3e2\u3c/sub\u3e]
In the search for new examples of systems that self-assemble into cyclic metal–organic architectures, the six isomers of X,Y′-bis(di(1H-pyrazolyl)methane)-1,1′-biphenyl, LXY, and their silver(I) trifluoromethanesulfonate complexes were prepared. Five of the six silver complexes gave crystals suitable for single crystal X-ray diffraction, with only the microcrystalline derivative of 2,3′-bis(di(1H-pyrazolyl)methane)-1,1′-biphenyl, L23, proving to be unsuitable for this analysis. Of the structurally characterized silver(I) complexes, that with L22 showed an unusual trans-spanning chelating coordination mode to silver. At the same time the ligand was also bound to a second silver center giving rise to a cyclic supramolecular isomer with a 22-membered metallacycle. The complex of L34 also gave a cyclic dication but with a remarkable 28-membered metallacycle ring. The remaining three derivatives were polymeric. The results of this study underscore that a 120° angle between dipyrazolylmethyl moieties across aromatic spacers will give rise to a cyclic dication but this is not an exclusive requirement for the formation of cyclic architectures. Also, the supramolecular structures of complexes are assembled via a variety of noncovalent interactions involving the di(pyrazolyl)methyl cation most notably by weak hydrogen bonding interactions involving the methine hydrogen and an oxygen atom of the triflate anion
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