Equilibrium Exchange Research Articles

Kinetic characterization of amino acid activation by aminoacyl-tRNA synthetases using radiolabelled γ-[32P]ATP.

Aminoacyl-tRNA synthetases (AARSs) are fundamental enzymes that pair amino acids and tRNAs for protein synthesis. Aminoacylation occurs in two discrete steps. The amino acid is first activated by ATP, leading to an aminoacyl-adenylate intermediate and pyrophosphate (PPi) formation. In a subsequent step, the aminoacyl moiety is transferred to the tRNA. Kinetic assays were developed to follow each of these steps independently, as well as cumulative two-step aminoacylation. The main advantage of following the activation step over two-step aminoacylation is that most AARSs can activate amino acids in the absence of the tRNA, the production of which is laborious. Hence, the activation step is often tested first in the kinetic analysis, including large screens exploring AARS-targeting inhibitors. Since the 1960s, the activation reaction has been routinely followed by the standard ATP/[32P]PPi exchange assay, which relies on the equilibrium exchange of radiolabel between PPi and ATP using [32P]PPi as a labelled compound. However, this method became much less convenient when [32P]PPi was discontinued in 2022. As a solution, we developed a modified assay that uses easily attainable γ-[32P]ATP as a labelled compound in the equilibrium-based assay. Using this assay, herein named the [32P]ATP/PPi assay, we followed the activation step of several AARSs. The obtained data are in good agreement with the previously published kinetic constants obtained with the standard ATP/[32P]PPi exchange assay.

The Real Equilibrium Exchange Rate of the Czech Koruna – the BEER Approach

The aim of this paper is to develop a model of the real equilibrium CZK/EUR exchange rate with all relevant explanatory variables. Emphasis will be placed on examining the longest possible time horizon, with a period of real convergence, but also economic stagnation. The model is based on the theoretical BEER approach using a cointegration or error correction model that distinguishes between short-term and long-term relationships. The results show that the Czech koruna strengthens when the productivity differential, terms of trade differential or gross fixed capital formation increase, while the koruna weakens when the VIX index representing global risk aversion increases. For the real interest rate differential, the hypothesis that the koruna strengthens in the short run during the improvement but weakens in the long run probably due to the country's risk premium, was confirmed. Moreover, it turned out that the start of the European Central Bank's quantitative easing led to strengthening of the Czech koruna, while the start of the CNB's foreign exchange interventions in 2013 led to weakening of the Czech koruna.

The determination of the exchange rate: A new-developmental approach

This paper discusses the long-term determination of the exchange rate, given that it may remain depreciated or overvalued for some time. It defines the equilibrium exchange rate and the competitive exchange rate; the latter makes investment projects competitive internationally. Instead of starting from the PPP theory, it starts from the concept of the value of foreign money or the exchange rate around which the price, the exchange rate, revolves according to the supply and demand of foreign money. This, in turn, is influenced by three factors: the terms of trade, the current-account balance as a determinant of the net capital flows or inflows, and the interest rate differential. This paper criticizes the “fundamental equilibrium” concept and develops two econometric tests. The first checks whether the four determinant variables used in the model are relevant. The second verifies whether this model is a good predictor of the exchange rate throughout time.

Adsorption and ion exchange of toxic metals by Brazilian clays: clay selection and studies of equilibrium, thermodynamics, and binary ion exchange modeling.

In this study, four Brazilian clays (Bofe, Verde-lodo, commercial Fluidgel, and expanded commercial vermiculite) were evaluated for their adsorptive capacity and removal percentage in relation to different toxic metals (Ni2+, Cd2+, Zn2+, and Cu2+). The best results were obtained by expanded vermiculite, with cadmium removal reaching values of 95%. The most promising clay was modified by the sodification process, and the metal cadmium was used to evaluate the ion exchange process. The clays expanded vermiculite (EV) and VNa-sodified vermiculite were evaluated by equilibrium study at 25, 35, and 45 °C. At 25 °C, EV obtained a maximum adsorption capacity of 0.368 mmol/g and sodified vermiculite 0.480 mmol/g, which represents an improvement of 30.4% in modified clay capacity. At 45 °C, the sodified vermiculite reached 0.970 mmol/g adsorption capacity. The Langmuir, Redlich-Peterson Freundlich, and Dubinin-Raduskevich models were adjusted to the results. Langmuir provided the best fit among the models. The thermodynamic quantities (ΔS, ΔH, and ΔG) demonstrated that the process is spontaneous and endothermic and the metal is captured by physisorption and chemisorption in the studied temperature range. For the ion exchange equilibrium, the binary Langmuir and binary Langmuir-Freundlich models were adjusted to the expanded vermiculite and sodified vermiculite isotherms, respectively. Both models were predictive. Thermal analysis indicated good heat resistance even after material modification. The apparent and real densities demonstrated that after each treatment or contamination, the clayey material undergoes contraction in its structure. An improved efficiency of the adsorbent was found after sodification.

Economic growth and deviations from the equilibrium exchange rate: a panel ARDL and panel NARDL approach

Economic growth and deviations from the equilibrium exchange rate: a panel ARDL and panel NARDL approach

Trace metal speciation trends in Mazowe dam, Zimbabwe, a typical sub-tropical dam ecosystem impacted by gold mining and agriculture.

The present study aimed to assess trace metal speciation trends in the water and sediments of Mazowe Dam, a typical sub-tropical dam ecosystem impacted by gold mining and agriculture in Zimbabwe. The elements studied include Al, As, Cd, Co, Cr, Cu, Hg, Fe, Mn, Ni, Pb, and Zn. Elemental speciation in the water column was determined using Visual MINTEQ version 3.1 geochemical computer modelling, while speciation in the sediment phase was determined using sequential extraction techniques. For each element, the data obtained were subjected to extensive correlation analysis to identify intra- and inter-metal species interactions in the water column and the sediment phase, as well as across the water-sediment interface. Possible mechanisms to account for the observed species interactions are proposed. In the water column, Co was predicted to have the highest number of chemical species (9), Cd and Zn (8), Mn and Fe (7), Ni (6), Pb (5), Al and Cu (3), Cr, Hg, and As have the least (2). In the sediment, Al, As, Co, Cr, Cu, Fe, Ni and Fe mainly exist in the residual fraction, while Zn and Mn concentrations in fractions vary per sampling site, with no fraction that is dominant across the sampling sites. Equilibrium exchange reactions across the water-sediment interface were observed e.g., for Cd species /FA2Cd (aq) and Co species /FACo+2G (aq), and /FA2Co (aq). This study is valuable in highlighting trace metal speciation in a tropical dam ecosystem in Africa and adds to the growing knowledge about the behaviour of trace metals in aquatic ecosystems in the region and globally.

Beyond symmetry: investigating the asymmetric impact of exchange rate misalignment on economic growth dynamics in Bangladesh

ABSTRACT This study examines the influences of asymmetry in exchange rate misalignment on economic growth of Bangladesh using utilizing time series data over the period from 1980 to 2020. The outcomes of the study symmetrically show that exchange rate misalignment has a significant impact on economic growth. In contrast, the adoption of NARDL technique gives substantial evidence for asymmetric effects, revealing that undervaluation supports economic growth while overvaluation hampers it. This analysis supports implementing a market-based equilibrium exchange rate system. It informs the regulators, policy makers, and market specialists that the customized exchange rate policies support sustained long-term economic growth.

CHEER and markets’ integration: evidence from selected East Asian economies

PurposeThis paper aims to investigate markets’ integration using the capital enhanced equilibrium exchange rate (CHEER) model for seven, highly competitive, East Asian countries.Design/methodology/approachThe sample consists of monthly observations, whereas unit root and cointegration techniques with structural shifts have been used.FindingsThe evidence shows that the weak form of the CHEER approach holds for Malaysia and Thailand. For China, Japan, Korea, Singapore and Taipei, only the uncovered interest parity condition is validated, implying capital markets integration. In contrast, for these five countries, the results indicate absence of goods’ markets integration. This outcome can be attributed to the impact of quite high non-tariff barriers and the Balassa–Samuelson effect.Originality/valueTo the best of the author’s knowledge, this is the first study that investigate markets’ integration in several East Asian economies, using the CHEER approach and more accurate price indices.

Exchange Policy and Misalignments in Morocco: A Quantitative Analysis

The research examines the equilibrium exchange rate and misalignment quantifications for the case of Morocco over the period 1990-2022. Based on an econometric model developed by Edwards in 1994, fundamental variables such as productivity, foreign direct investment (FDI), inflation and the real interest rate (RIR) are analysed to estimate the equilibrium value of the real exchange rate (REER) of the Moroccan dirham. The results show a cointegration between the REER and the fundamental variables, indicating the existence of a long-term relationship. The analysis of misalignments reveals periods of overvaluation and undervaluation of the Moroccan dirham, influenced by economic factors and monetary policies. This study has important implications for economic and monetary policy in Morocco, particularly with regard to export competitiveness and macroeconomic stability.

Reversible assembly and disassembly of V-ATPase during the lysosome regeneration cycle.

Regulation of the luminal pH of late endocytic compartments in continuously fed mammalian cells is poorly understood. Using normal rat kidney fibroblasts, we investigated the reversible assembly/disassembly of the proton pumping V-ATPase when endolysosomes are formed by kissing and fusion of late endosomes with lysosomes and during the subsequent reformation of lysosomes. We took advantage of previous work showing that sucrosomes formed by the uptake of sucrose are swollen endolysosomes from which lysosomes are reformed after uptake of invertase. Using confocal microscopy and subcellular fractionation of NRK cells stably expressing fluorescently tagged proteins, we found net recruitment of the V1 subcomplex during sucrosome formation and loss during lysosome reformation, with a similar time course to RAB7a loss. Addition of invertase did not alter mTORC1 signalling, suggesting that the regulation of reversible V-ATPase assembly/disassembly in continuously fed cells differs from that in cells subject to amino acid depletion/refeeding. Using live cell microscopy, we demonstrated recruitment of a fluorescently tagged V1 subunit during endolysosome formation and a dynamic equilibrium and rapid exchange between the cytosolic and membrane bound pools of this subunit. We conclude that reversible V-ATPase assembly/disassembly plays a key role in regulating endolysosomal/lysosomal pH in continuously fed cells.

Exchange rates and fundamentals: Forecasting with long maturity forward rates

We show that in a popular model of exchange rate determination, the unobserved expected future exchange rate can be substituted with the observed forward exchange rate. This allows the derivation of a new error-correction forecasting model, which approximates the gap between the fundamental equilibrium exchange rate and the actual exchange rate with the long-maturity forward exchange rate. Our out-of-sample forecasting results for major currencies are unprecedented. The forecasting model is simple, easy to replicate, and the data we use are available in real time and not subject to revisions.

Oxygen exchange kinetics on La0.6Sr0.4FeO3−δ

Equilibrium properties and kinetic properties of strontium-doped lanthanum ferrite La0.6Sr0.4FeO3−δ were studied by an original approach involving two methods: oxygen partial pressure relaxation (with determination of equilibrium exchange rate R0 and a chemical diffusion coefficient in oxide: Dchem) and a quasi-equilibrium oxygen release [with construction of equilibrium isothermal diagram “lg pO2 vs. (3 − δ) vs. T”]. Activation energies determined for R0 and Dchem were 120 ± 20 and 30 ± 2 kJ/mol, respectively. It was shown that the linear free-energy relationship—between activation energy of the reaction rate constant and standard Gibbs energy of the reaction—is of the Brønsted–Evans–Polanyi type.

Mobility capillary electrophoresis-native mass spectrometry reveals the dynamic conformational equilibrium of calmodulin and its complexes.

Benefitting from the rapid evolution of artificial intelligence and structural biology, an expanding collection of high-resolution protein structures has greatly improved our understanding of protein functions. Yet, proteins are inherently flexible, and these static structures can only offer limited snapshots of their true dynamic nature. The conformational and functional changes of calmodulin (CaM) induced by Ca2+ binding have always been a focus of research. In this study, the conformational dynamics of CaM and its complexes were investigated using a mobility capillary electrophoresis (MCE) and native mass spectrometry (native MS) based method. By analyzing the ellipsoidal geometries of CaM in the solution phase at different Ca2+ concentrations, it is interesting to discover that CaM molecules, whether bound to Ca2+ or not, possess both closed and open conformations. Moreover, each individual CaM molecule actively "jumps" (equilibrium exchange) between these two distinct conformations on a timescale ranging from milli- to micro-seconds. The binding of Ca2+ ions did not affect the structural dynamics of CaM, while the binding of a peptide ligand would stabilize CaM, leading to the observation of a single, compact conformation of the resulting protein complex. A target recognition mechanism was also proposed based on these new findings, suggesting that CaM's interaction with targets may favor a conformational selection model. This enriches our understanding of the binding principles between CaM and its numerous targets.

Does exchange rate misalignments lead changes in macroeconomic fundamentals?

This article aimed at verifying the reliability of equilibrium exchange rate (EER) concepts by exploring if exchange rate misalignments are leading to changes in macroeconomic fundamentals. The authors focused on G10 currencies and the three most popular EER models which the IMF regularly uses within the External Balance Assessment: Purchasing Power Parity, Behavioural EER and Fundamental EER. In methodological terms, the study applied the cross-sectional predictability approach developed by Sarno and Schmeling (2014), which ranks countries on the basis of the scale of EER misalignment to check if this ranking helps to predict key macro variables. The results indicate that EER misalignment contains cross-sectional predictive power and allows forecasting real effective exchange rates, short-term interest rates and current account balance differences across countries.

Perhitungan Sederhana Nilai Tukar Riil Rupiah dan Keseimbangannya

For the public and private sectors, especially those dealing with the international world, monitoring exchange rate movements is very important. However, in the current conditions of volatility, uncertainty, complexity and ambiguity (VUCA), exchange rate projections become very challenging. Behavioral Equilibrium Exchange Rate (BEER) is a model used to estimate an exchange rate that is considered balanced based on fundamental factors. In connection with this, the author intends to inform you about BEER and its benefits. Therefore, this paper aims to estimate the balance of the real exchange rate (RER), so that exchange rate movements outside of equilibrium (misalignment) can be identified. The method used in this paper is the Error Correction Model (ECM). The author uses quarterly data with the aim of getting a long data series and more accurate estimation results. Meanwhile, the explanatory variables consist of productivity, interest rate differential, foreign reserves, terms of trade, and risk premium. From the estimation results, it is known that changes in productivity, interest rate differential and foreign exchange reserves have a significant positive effect on RER movements. The risk premium has a significant negative effect, while the terms of trade are not significant. It is hoped that the results of this simple analysis will provide additional insight for policy makers and economic practitioners in understanding the dynamics of the real rupiah exchange rate and efforts to maintain its stability. It is also hoped that this article will provide a strong basis for considering more effective policies in managing the rupiah exchange rate.
 Keywords: exchange rate, equilibrium, fundamental factor, flexibility

Extrudable Covalently Cross‐Linked Thio‐Urethane Liquid Crystalline Elastomers

AbstractLiquid crystalline elastomer networks cross‐linked by dynamic covalent bonds (xLCEs) possess the remarkable capability of being (re)processed during plastic flow at high temperatures, while also allowing for the (re)programming of their local alignment. However, the current generation of xLCEs cannot be extruded directly into filaments or injection‐molded into shapes capable of actuation. Here, a novel poly(thio‐urethane) (PTU) LCE thermoset is presented. The inclusion of dibutyltin dilaurate as a catalyst enables the manipulation of the elastic–plastic transition through two distinct pathways. The dissociative equilibrium exchange between the thio‐urethane linkage to form separate thiol and isocyanate competes with the associative exchange of thio‐urethane and a free isocyanate or thiol groups. The temperature of fast plastic flow onset is ≈160 ˚C, and the associated bond‐exchange activation energy is ≈54 kJ mol−1. The hydrogen bonding below the elastic‐plastic transition makes the elastomer robust and extremely ductile with a failure strain exceeding 600% and a Shore hardness A of 72, preventing any creep during cyclic thermal actuation. The versatility of this dynamically cross‐linked elastomer is successfully demonstrated by extruding it using a commercial twin‐screw extruder, injection molding it into required shapes, and hot‐pressing it into flat films or shapes.

Measuring RMB equilibrium exchange rate and misalignment in China: Application of BEER and PEER approaches

The study attempts to measure RMB real effective exchange rate (REER) equilibrium and its associated degree of misalignments for China using the behavioral equilibrium exchange rate (BEER) and permanent equilibrium exchange rate approaches. We use a range of economic fundamentals and employ yearly data covering the period 1980–2020, and apply the Johansen Cointegration test and other econometric methods for the study purpose. We find evidence of the existence of RMB real effective exchange rate equilibrium, and for most of the periods, the RMB REER is closer to its equilibrium level. We also find that the RMB REER misaligned with its equilibrium producing episodes of undervaluation and overvaluation, but the magnitude of the misalignments is small and the BEER approach produces a lower degree of misalignments. This suggests that the RMB undervaluation is moderate and not as exaggerated. We identify that the economic fundamentals used in this study are important determinants of RMB real effective exchange rate equilibrium. In line with the above, the study recommends that China may continue using its RMB exchange rate as its policy tool, but the policymakers should focus on the core fundamentals that derived the equilibrium exchange rate.

Risk-off shocks and spillovers in safe havens

This paper examines real and financial spillovers to safe haven financial flow destinations due to risk-off shocks in global financial markets. Using country-specific structural vector autoregression (VAR) models over the period 1990 to 2021, we show that dynamics for Japan appear to be different to those of Switzerland and the US in three main ways. First, in response to risk-off episodes, the yen real effective exchange rate (REER) appreciated significantly, with the effect persisting for around 25 days. Second, no significant effects on portfolio flows to Japan are found, in spite of the exchange rate effects, suggesting a rapid adjustment of financial markets to shifts in equilibrium exchange rates. Third, negative real spillovers from risk-off shocks appear to only apply to Japan with exchange rate appreciation exacerbating declines in GDP growth. Our findings have important implications for policymakers in safe haven destinations in managing domestic financial vulnerabilities associated with risk-off episodes.

Assessment of Fiji’s exchange rate

This paper empirically estimates Fiji’s bilateral equilibrium real exchange rate with two of its key trading partners, the US and Australia. Applying the Behavioural Equilibrium Exchange Rate (BEER) approach, we estimate the equilibrium exchange rate by considering the productivity differential, real interest rate differential, net foreign assets, money supply, and terms of trade. Using monthly data from March 2011 to September 2022 and a system approach to cointegration, a strong relationship between the real exchange rate and its fundamentals is found, but importance of factors differed by trading partner. Our findings show that the Fijian Dollar has been undervalued against both US Dollar and Australian Dollar in recent years, but to varying degrees. Our analysis underlines the importance of assessing bilateral exchange rate misalignments in basket pegs when devising exchange rate policy.

The behavior of the real effective exchange rate of Ethiopia: does misalignment exist?

ABSTRACT This study examined the main drivers of real effective exchange rate (REER) misalignment for Ethiopia over the period 1970–2020. Based on the behavioural equilibrium exchange rate concept, the study used the dynamic OLS and Markov regime switching model (MSM). The cointegration results revealed that the REER appreciates for an increase in relative productivity, government spending and net remittances, but it depreciates for more trade openness and real investment in the long-run. The MSM results also suggested a distinct misalignment episodes of under- and overvaluation with significant variability for the Ethiopia’s Birr over the study period.