Measuring population mobility speed from space

Ad-hoc population dynamics in Krugman’s type core and periphery models adjust population share of a region, based on its real wage rate deviation from national average, at pre-specified speed of population mobility. Whereas speed of population mobility is expected to be different across countries, for geographical, cultural, technological, etc. reasons, one common speed is often applied in theoretical and simulation analysis, due to spatially patchy, and temporally infrequent, availability of sub-national regional data. This article demonstrates how, increasingly available, high definition spatio-temporal remote-sensing data, and their by-products, can be used to measure speed of population mobility in national and sub-national level.

Explanation of changes in real estate stock market

The aim of this study is to explain the changes in the real estate prices as well as in the real estate stock market prices, using some macro-economic explanatory variables, such as the gross domestic product (GDP), the real interest rate and the unemployment rate. Several regressions have been carried out in order to express some types of incremental and absolute deflated real estate lock market indexes in terms of the macro-economic variables. The analyses are applied to the Swedish economy. The period under study is 1984-1994. Time series on monthly data are used. i.e. the number of data-points is 132. If time leads/lags are introduced in the e regressions, significant improvements in the already high correlations are achieved. The signs of the coefficients for IR, UE and GDP are all what one would expect to see from an economic point of view: those for GDP are all positive, those for both IR and UE are negative. All the regressions have high R2 values. Both markets anticipate change in the unemployment rate by 6 to 9 months, which seems reasonable because such change can be forecast quite reliably. But, on the contrary, there is no reason why they should anticipate by 3-6 months changes in the interest rate that can hardly be reliably forecast so far in advance.

Fractionation factors and activation energies for exchange of the low barrier hydrogen bonding proton in peptidyl trifluoromethyl ketone complexes of chymotrypsin

NMR investigations have been carried out of complexes between bovine chymotrypsin Aα and a series of four peptidyl trifluoromethyl ketones, listed here in order of increasing affinity for chymotrypsin: N-Acetyl-l-Phe-CF3, N-Acetyl-Gly-l-Phe-CF3, N-Acetyl-l-Val-l-Phe-CF3, and N-Acetyl-l-Leu-l-Phe-CF3. The D/H fractionation factors (φ) for the hydrogen in the H-bond between His 57 and Asp 102 (His 57-Hδ1) in these four complexes at 5°C were in the range φ = 0.32–0.43, expected for a low-barrier hydrogen bond. For this series of complexes, measurements also were made of the chemical shifts of His 57-Hɛ1 (δ2,2-dimethylsilapentane-5-sulfonic acid 8.97–9.18), the exchange rate of the His 57-Hδ1 proton with bulk water protons (284–12.4 s−1), and the activation enthalpies for this hydrogen exchange (14.7–19.4 kcal⋅mol−1). It was found that the previously noted correlations between the inhibition constants (Ki 170–1.2 μM) and the chemical shifts of His 57-Hδ1 (δ2,2-dimethylsilapentane-5-sulfonic acid 18.61–18.95) for this series of peptidyl trifluoromethyl ketones with chymotrypsin [Lin, J., Cassidy, C. S. & Frey, P. A. (1998) Biochemistry 37, 11940–11948] could be extended to include the fractionation factors, hydrogen exchange rates, and hydrogen exchange activation enthalpies. The results support the proposal of low barrier hydrogen bond-facilitated general base catalysis in the addition of Ser 195 to the peptidyl carbonyl group of substrates in the mechanism of chymotrypsin-catalyzed peptide hydrolysis. Trends in the enthalpies for hydrogen exchange and the fractionation factors are consistent with a strong, double-minimum or single-well potential hydrogen bond in the strongest complexes. The lifetimes of His 57-Hδ1, which is solvent shielded in these complexes, track the strength of the hydrogen bond. Because these lifetimes are orders of magnitude shorter than those of the complexes themselves, the enzyme must have a pathway for hydrogen exchange at this site that is independent of dissociation of the complexes.

Regulation of Apoplastic NH4+ Concentration in Leaves of Oilseed Rape1

Regulation of apoplastic NH4+ concentration in leaves of oilseed rape (Brassica napus L.) was studied using a vacuum-infiltration technique that allowed controlled manipulations of the apoplastic solution. In leaves infiltrated with NH4+-free solution, the apoplastic NH4+ concentration returned in less than 1.5 min to the preinfiltration level of 0.8 mm. Infiltrated 15NH4+ was rapidly diluted by 14NH4+/14NH3 effluxed from the cell. The exchange rate of 15N/14N over the apoplast due to combined 14N efflux from the symplast and 15N influx from the apoplastic solution was 29.4 μmol g−1 fresh weight h−1 between 0 and 5 min after infiltration. The net uptake of NH4+ into the leaf cells increased linearly with apoplastic NH4+ concentrations between 2 and 10 mm and could be partially inhibited by the channel inhibitors La3+ and tetraethylammonium and by Na+ and K+. When apoplastic pH increased from 5.0 to 8.0, the steady-state apoplastic NH4+ concentration decreased from 1.0 to 0.3 mm. Increasing temperature increased the rate of NH4+ net uptake and reduced the apoplastic steady-state NH4+ concentration. We conclude that the apoplastic solution in leaves of oilseed rape constitutes a highly dynamic NH4+ pool.

Alfabetização no ensino fundamental: novas bases curriculares

Esta dissertação apresenta dados e discussões oriundos de uma experiência coletiva de pesquisa cujo objetivo maior consistiu em articular as bases curriculares da alfabetização no ensino fundamental de nove anos. A partir da transição histórica e política ocorrida pela Lei 11.274/1996, na qual o ensino fundamental passou a ter um ano a mais de duração e a receber as crianças que anteriormente eram atendidas na educação infantil, uma nova configuração se fez necessária. Demonstramos ao longo do trabalho a necessidade de: 1. Um plano que considere as transições (seja entre anos ou entre ciclos) e que sustente as continuidades; 2. Assumir, a partir do ano de ingresso no ensino fundamental, a perspectiva do regime de ciclo, definindo responsabilidades, objetivos e estratégias articuladas a partir de um trabalho em equipe; 3. Aprofundar conhecimentos que permitam considerar os aspectos mais subjetivos da relação educativa, considerando sempre a infância em seu encantamento lúdico; 4. Estabelecer uma relação dinâmica e produtiva entre oralidade e escrita, entre língua e literatura; 5. Dar maior precisão ao manejo da heterogeneidade desde a série de ingresso enfatizando o acompanhamento de singularidades e diferenças como forma de resolver o problema dos desníveis em alfabetização. A perspectiva teórica parte da articulação de várias áreas e temas do conhecimento: a história da escrita; pesquisa sobre oralidade ou cultura oral em tensão com a escrita; a psicanálise e a educação. Pretendemos, a partir das experiências e reflexões apresentadas nesse trabalho, contribuir para as políticas públicas enfatizando a grande relevância do ensino da escrita e da leitura nas séries iniciais do ensino fundamental. Ao longo dessas experiências, constatamos que, para formar leitores e escritores de bom nível na escola pública brasileira, precisamos de um modelo de trabalho coletivo mais complexo, capaz de exercer um manejo pedagógico detalhado, e ampliamos nossa consciência de que nossas buscas metodológicas, nossas experiências e nossos esforços coletivos em torno da heterogeneidade, apesar de consistentes e relevantes, só poderão ser sustentados a partir de uma reorganização do trabalho escolar que insista em fazer da alfabetização e da leitura uma verdadeira prioridade.

Impact of artifact correction methods on R-R interbeat signals to quantifying heart rate variability (HRV) according to linear and nonlinear methods.

In the analysis of heart rate variability (HRV) are used temporal series that contains the distances between successive heartbeats in order to assess autonomic regulation of the cardiovascular system. These series are obtained from the electrocardiogram (ECG) signal analysis, which can be affected by different types of artifacts leading to incorrect interpretations in the analysis of the HRV signals. Classic approach to deal with these artifacts implies the use of correction methods, some of them based on interpolation, substitution or statistical techniques. However, there are few studies that shows the accuracy and performance of these correction methods on real HRV signals. This study aims to determine the performance of some linear and non-linear correction methods on HRV signals with induced artefacts by quantification of its linear and nonlinear HRV parameters. As part of the methodology, ECG signals of rats measured using the technique of telemetry were used to generate real heart rate variability signals without any error. In these series were simulated missing points (beats) in different quantities in order to emulate a real experimental situation as accurately as possible. In order to compare recovering efficiency, deletion (DEL), linear interpolation (LI), cubic spline interpolation (CI), moving average window (MAW) and nonlinear predictive interpolation (NPI) were used as correction methods for the series with induced artifacts. The accuracy of each correction method was known through the results obtained after the measurement of the mean value of the series (AVNN), standard deviation (SDNN), root mean square error of the differences between successive heartbeats (RMSSD), Lomb\'s periodogram (LSP), Detrended Fluctuation Analysis (DFA), multiscale entropy (MSE) and symbolic dynamics (SD) on each HRV signal with and without artifacts. The results show that, at low levels of missing points the performance of all correction techniques are very similar with very close values for each HRV parameter. However, at higher levels of losses only the NPI method allows to obtain HRV parameters with low error values and low quantity of significant differences in comparison to the values calculated for the same signals without the presence of missing points.

Adsorption and first stages of polymerization of aniline on platinum single crystal electrodes

The present communication studies the adsorption of aniline on platinum single crystal electrodes and the electrochemical properties of the first layers of polyaniline(PANI) grown on those platinum surfaces. The adsorption process was studied in aqueous acidic solution (0.1 M HClO4) and the electrochemical properties of thin films of PANI in both aqueous (1 M HClO4) and non-aqueous media (tetrabutyl ammonium hexafluorophosphate (TBAPF6) with additions of methanesulphonic acid in acetonitrile). First of all, it was found that the adsorption of aniline on platinum single crystal surfaces is a surface sensitive process, and even more important that the adsorption features found at low concentrations (5 × 10−5 M) can be directly correlated to the electrochemical properties of thin films of PANI in the very early stages of polymerization. The Pt(1 1 0) surface was found to be more suitable to obtain polymers with more reversible redox transitions when studied in aqueous media (1 M HClO4). This is in good agreement with the higher polymerization rates found on this surface compared to Pt(1 0 0) and Pt(1 1 1). Finally the differences in ionic exchange rate were greatly enhanced when they were studied in organic media. The AC 250 Hz response in the case of the thin films synthesized on Pt(1 1 0) is about twice greater than that obtained in the other basal planes using polymer layers with the same thickness.

International Capital Flows and Monetary Policy Spillovers

This dissertation examines the drivers and implications of international capital flows. The overarching motivation is the observation that countries not at the centre of global financial markets are subject to considerable spillovers from centre countries, notably from their monetary policy. I present new empirical evidence on the determinants of the observed patterns of international capital flows and monetary policy spillovers, and study their effect on both financial markets and the real economy. In Chapter 2 I provide evidence on the determinants of a puzzling negative correlation observed between productivity growth and net capital inflows to developing and emerging market economies (EMEs) since 1980. By disaggregating net capital inflows into their gross components, I show that this negative correlation is explained by capital outflows related to purchases of very liquid assets from the fastest growing countries. My results suggest a desire for international portfolio diversification in liquid assets by fast growing countries is driving much of the original puzzle. In the reminder of my dissertation I pivot to study the foreign characteristics that drive international capital flows and monetary policy spillovers, with a particular focus on the role of unconventional monetary policy in the United States (U.S.). In Chapter 3 I show that a significant portion of the heterogeneity in EMEs' asset price adjustment following the quantitative easing operations by the Federal Reserve (the Fed) during 2008-2014 can be explained by the degree of bilateral capital market frictions between these countries and the U.S. This is true even after accounting for capital controls, exchange rate regimes, and domestic monetary policies. Chapter 4, co-authored with Michal Ksawery Popiel, studies unconventional monetary policy in a small open economy, looking specifically at the case of Canada since the global financial crisis. We quantify the effect Canadian unconventional monetary policy shocks had on the real economy, while carefully controlling for and quantifying spillovers from U.S. unconventional monetary policy. Our results indicate that the Bank of Canada's unconventional monetary policy increased Canadian output significantly from 2009-2010, but that spillovers from the Fed's policy were even more important for increasing Canadian output after 2008.

The EMS Crisis of the 1990s: Parallels with the present crisis? CEPS Working Document No. 393, 28 March 2014

The EMS crisis of the 1990s illustrated the importance of a lack of confidence in price or exchange rate stability, whereas the present crisis illustrates the importance of a lack of confidence in fiscal sustainability. Theoretically the difference between the two should be minor since, in terms of the real return to an investor, the loss of purchasing power can be the same when inflation is unexpectedly high, or when the nominal value of government debt is cut in a formal default. Experience has shown, however, that expropriation via a formal default is much more disruptive than via inflation. The paper starts by providing a brief review of the EMS crisis, emphasising that the most interesting period might be the ‘post-EMS’ crisis of 1993-95. It then reviews in section 2 the crisis factors, comparing the EMS crisis to today’s euro crisis. Section 3 outlines the main analytical issue, namely the potential instability of high public debt within and outside a monetary union. Section 4 then compares the pressure on public finance coming from the crises for the case of Italy. Section 5 uses data on ‘foreign currency’ debt to disentangle expectations of devaluation/inflation from expectations of default. Section 6 concludes.

Le role des politiques monétaires et la convergence macroeconomique sur le développement des systèmes financiers dans les pays du sud de la Méditerranée. = The role of monetary policies and macroeconomic convergence in the development of financial systems in south Mediterranean countries. MEDPRO Technical Report No. 12/April 2012

This MEDPRO Technical Report shows that the monetary and exchange rate policies conducted by central banks in the South Mediterranean region display apparent homogeneity in their operational frameworks, albeit with some specificities and differing degrees of advancement. While central banks state that price stability is their ultimate objective, failures to control interest rates as operational objectives of monetary policy result in monetary authorities resorting to quantitative approaches to monetary policy, meaning that monetary aggregates and credit targets are being used as intermediate targets of monetary policy. An econometric exercise limited to Maghreb countries (Algeria, Morocco, and Tunisia) has been conducted to analyse the potential scenarios of convergence and monetary policy coordination. Given the high structural heterogeneity and the slow pace of real convergence due to weak commercial integration in the Maghreb, results nevertheless show alternative dynamics in the integration of effective nominal exchange rates, as well as a complete convergence dynamic in exchange rate policies. Partial convergence of monetary policies regarding the stabilisation of inflation rates remains an open option for a transitional phase where financial integration is low.

Les enjeux de la libéralisation des comptes de capital dans les pays du sud de la Méditerranée. = Challenges arising from Capital Account Liberalisation in the Countries of the South Mediterranean Region. MEDPRO Technical Report No. 11/March 2012

This MEDPRO Technical Report confirms the importance of commercial openness and macroeconomic performance (i.e. the control of inflation and stability of current account balance and exchange rate) on growth dynamics in the south Mediterranean countries. In particular, the positive impact of capital account liberalisation is conditioned by the imperative reinforcement of institutional quality, country risk reduction, and government stability. An examination of the Tunisian case shows that only sectors subject to tariff dismantlement within the framework of the Association Agreement with the EU appear to benefit from capital account liberalisation. Furthermore, the report shows that a scenario of capital account liberalisation requires the anticipation of monetary policy reaction functions. It follows that the mechanisms for interest rate adjustment, or inter alia, the interest rates’ reaction to price fluctuations, are weakly volatile. In turn, the analysis shows that an active control of inflation mismatches occurs essentially through exchange rate corrections, thus highlighting the greater interest central banks have in exchange rate stability over real stability. A capital account liberalisation scenario would hence impose a tightening of monetary policy.

The price elasticity of the Euro to movements in foreign reserves through European Central Bank intevention

The Euro has been used as the largest weighting element in a basket of currencies for forex arrangements adopted by several Central European countries outside the European Union (EU). The paper uses a new time-series approach to examine the relationship between the Euro exchange rate and the level of foreign reserves. It employs Zero-no-zero (ZNZ) patterned vector error-correction (VECM) modelling to investigate Granger causal relations among foreign reserves, the European Monetary Union money supply and the Euro exchange rate. The findings confirm that foreign reserves may influence movements in the Euro's exchange rate. Further, ZNZ patterned VECM modelling with exogenous variables is used to estimate the amount of foreign reserves currently required in order to again achieve a targetted Euro exchange rate

DOSY NMR studies of chemical exchange behavior of poly(2-hydroxyethyl methacrylate)

PFG-NMR was used to study the chemical exchange of linear PHEMA having a range of molecular weights with water in DMSO containing varying quantities of water. The aim was to investigate the use of PFG-NMR to study chemical exchange between a polymer with exchangeable protons and a small fast diffusing molecule to provide insight into the conformation adopted by a polymer in solution. The experimental data were simulated closely for the two-site exchange case using the Bloch equations modified for chemical exchange and diffusion. The exchange rate could be used to detect changes in polymer conformation resulting from changes in the solvent. PHEMA of MW 10 000 showed significant time-dependent changes in exchange rate, resulting from preferential solvation of the OH sites by water, and subsequent conformational changes which altered accessibility of the OH sites to water. This behavior was not observed for larger MW PHEMA, which adopted a stable conformation immediately. Large changes in the exchange rate were not reflected in changes to the hydrodynamic radius, suggesting that a minimal overall change in the chain dimensions occurred. DMSO was found to be a poor solvent for PHEMA, which adopts a compact conformation in DMSO. This work has demonstrated that PFG-NMR is a sensitive method for detecting subtle changes in polymer conformation in polymers with exchangeable protons.

An improved novelty criterion for resource allocating networks

Online model order complexity estimation remains one of the key problems in neural network research. The problem is further exacerbated in situations where the underlying system generator is non-stationary. In this paper, we introduce a novelty criterion for resource allocating networks (RANs) which is capable of being applied to both stationary and slowly varying non-stationary problems. The deficiencies of existing novelty criteria are discussed and the relative performances are demonstrated on two real-world problems : electricity load forecasting and exchange rate prediction.

Volatility changes in drachma exchange rates

In January 2001 Greece joined the eurozone. The aim of this article is to examine whether an intention to join the eurozone had any impact on exchange rate volatility. We apply the Iterated Cumulative Sum of Squares (ICSS) algorithm of Inclan and Tiao (1994) to a set of Greek drachma exchange rate changes. We find evidence to suggest that the unconditional volatility of the drachma exchange rate against the dollar, British pound, yen, German mark and ECU/Euro was nonstationary, exhibiting a large number of volatility changes prior to European Monetary Union (EMU) membership. We then use a news archive service to identify the events that might have caused exchange rate volatility to shift. We find that devaluation of the drachma increased exchange rate volatility but ERM membership and a commitment to joining the eurozone led to lower volatility. Our findings therefore suggest that a strong commitment to join the eurozone may be sufficient to reduce some exchange rate volatility which has implications for countries intending to join the eurozone in the future.