Exchange Rates and Markov Switching Dynamics

This article presents a systematic and extensive empirical study on the presence of Markov switching dynamics in three dollar-based exchange rates. A Monte Carlo approach is adopted to circumvent the statistical inference problem inherent to the test of regime-switching behavior. Two data frequencies, two sample periods, and various specifications are considered. Quarterly data yield inconclusive evidence - the test rejects neither random walk nor Markov switching. Monthly data, on the other hand, offer unambiguous evidence of the presence of Markov switching dynamics. The results suggest that data frequency, in addition to sample size, is crucial for determining the number of regimes.exchange rate dynamics, regime switching, Monte Carlo Test, sampling frequency

Exchange rates and Markov switching dynamics

This article presents a systematic and extensive empirical study on the presence of Markov switching dynamics in three dollar-based exchange rates. A Monte Carlo approach is adopted to circumvent the statistical inference problem inherent to the test of regime-switching behavior. Two data frequencies, two sample periods, and various specifications are considered. Quarterly data yield inconclusive evidence; the test rejects neither random walk nor Markov switching. Monthly data, on the other hand, offer unambiguous evidence of the presence of Markov switching dynamics. The results suggest that data frequency, in addition to sample size, is crucial for determining the number of regimes. KEY WORDS

In Vivo Veritas - 18F-radiolabeled glycomimetics allow insights into the pharmacological fate of galectin-3 inhibitors

Glycomimetic drugs have attracted increasing interest as unique targeting vectors or surrogates for endogenous biomolecules. However, it is generally difficult to determine the in vivo pharmacokinetic profile of these compounds. In this work, two galectin-3 inhibitors were radiolabeled with fluorine-18 and used as surrogate PET tracers of TD139 and GB1107. Both compounds are promising drugs for clinical applications. In vivo evaluation revealed that both surrogates strongly differed with respect to their biodistribution profile. The disaccharide (TD139 surrogate) was rapidly eliminated from blood while the monosaccharide (GB1107 surrogate) showed no sign of excretion. The data obtained allowed us to infer the different in vivo fate of TD139 and GB1107 and rationalize how different administration routes could boost efficacy. Whereas the fast excretion profile of the TD139 surrogate indicated that systemic application of disaccharides is unfavorable, the extended biological half-life of the GB1107 surrogate indicated that systemic administration is possible for monosaccharides