Snakes and ladders in an inhomogeneous neural field model

Continuous neural field models with inhomogeneous synaptic connectivities are known to support traveling fronts as well as stable bumps of localized activity. We analyze stationary localized structures in a neural field model with periodic modulation of the synaptic connectivity kernel and find that they are arranged in a snakes-and-ladders bifurcation structure. In the case of Heaviside firing rates, we construct analytically symmetric and asymmetric states and hence derive closed-form expressions for the corresponding bifurcation diagrams. We show that the ideas proposed by Beck and co-workers to analyze snaking solutions to the Swift-Hohenberg equation remain valid for the neural field model, even though the corresponding spatial-dynamical formulation is non-autonomous. We investigate how the modulation amplitude affects the bifurcation structure and compare numerical calculations for steep sigmoidal firing rates with analytic predictions valid in the Heaviside limit

Financial locations : Frankfurt’s place and perspectives

The introduction of a common currency as well as the harmonization of rules and regulations in Europe has significantly reduced distance in all its guises. With reduced costs of overcoming space, this emphasizes centripetal forces and it should foster consolidation of financial activity. In a national context, as a rule, this led to the emergence of one financial center. Hence, Europeanization of financial and monetary affairs could foretell the relegation of some European financial hubs such as Frankfurt and Paris to third-rank status. Frankfurt’s financial history is interesting insofar as it has lost (in the 1870s) and regained (mainly in the 1980s) its preeminent place in the German context. Because Europe is still characterized by local pockets of information-sensitive assets as well as a demand for variety the national analogy probably does not hold. There is room in Europe for a number of financial hubs of an international dimension, including Frankfurt

Practice and prospects of medium-term economic forecasting

Government agencies and other national and international institutions are asked to perform forecasts over the medium term. In particular, the EU Stability and Growth Pact contains the obligation to formulate stability programmes over four years, covering a general economic outlook as well as the projected development of public finances. However, the current practice of performing medium-term economic projections is unsatisfactory from a methodological point of view as the applied methodology has been developed for short-run forecasting and it is questionable whether these methods are useful for the medium term. In particular, currently medium-term projections are mostly based on the neoclassical Solow growth model with an aggregate production function with labour, capital, and exogenous technological progress. It might be argued, however, that for medium-run projections endogenous growth models might be better suited. In this paper we give an overview of currently used methods for medium-term macroeconomic projections. Then we analyse the performance of medium-term forecasts for Austria to illustrate the strengths and weaknesses of the typical approach. In particular, the five-year projections of real GDP growth, inflation and the unemployment rate are investigated. Finally, we describe some approaches to improve medium-run projections.Econometric models, Macroeconomic forecasts, Aggregate production function, Austria

Practice and Prospects of Medium-term Economic Forecasting

Government agencies and other national and international institutions are asked to perform forecasts over the medium term. In particular, the EU Stability and Growth Pact contains the obligation to formulate stability programmes over four years, covering a general economic outlook as well as the projected development of public fi nances. However, the current practice of performing medium-term economic projections is unsatisfactory from a methodological point of view as the applied methodology has been developed for short-run forecasting and it is questionable whether these methods are useful for the medium term. In particular, currently medium-term projections are mostly based on the neoclassical Solow growth model with an aggregate production function with labour, capital, and exogenous technological progress. It might be argued, however, that for medium-run projections endogenous growth models might be better suited. In this paper we give an overview of currently used methods for medium-term macroeconomic projections. Then we analyse the performance of medium-term forecasts for Austria to illustrate the strengths and weaknesses of the typical approach. In particular, the fi ve-year projections of real GDP growth, infl ation and the unemployment rate are investigated. Finally, we describe some approaches to improve medium-run projections.Econometric models; macroeconomic forecasts; aggregate production function; Austria

Transport of the precursor to neurospora ATPase subunit 9 into yeast mitochondria

Isolated yeast mitochondria were able to take up Neurospora ATPase subunit 9 in vitro although the homologous yeast protein is synthesized within the mitochondria and inserted into the membrane from the matrix side (Tzagoloff, A., and Meagher, P. (1972) J. Biol. Chem. 247, 594- 603). The transfer of the protein was dependent on an energized mitochondrial inner membrane. It was accompanied by proteolytic processing of the precursor to the mature protein with the correct NH2 terminus as determined by Edman degradation of the transferred protein. The possibility is discussed that there are common features in the uptake machinery neither specific for one species nor specific for individual precursor proteins in the same species

Choosing and using payment instruments: evidence from German microdata

Germans are still very fond of using cash. Of all direct payment transactions, cash accounts for an astounding 82% in terms of number, and for 58% in terms of value. With a new and unique dataset that combines transaction information with survey data on payment behaviour of German consumers, we shed light on how individuals choose payment instruments and why cash remains so important. We propose a two-stage empirical framework which jointly explains credit card ownership and the use of cash. Our results indicate that the pattern of cash usage is compatible with systematic economic decision making. Consumers decide upon the adoption of payment cards and then use available payment media according to their transaction and personal characteristics, the relative costs of cash and card usage, and their assessment of payment instruments’ characteristics. Whereas older consumers use significantly more cash, the comparison with younger consumers shows that the difference in payment behaviour is not explained by age as such but to a large extent by differences in the characteristics of these two groups. It is interesting that the possession of a credit card, especially alongside a debit card, does not significantly affect the use of cash in Germany. JEL Classification: E41, E58, D12cash substitution, cash usage, credit cards, debit cards, payment behaviour, payment cards, payment innovation, Payment instruments, survey data

Choosing and using payment instruments: evidence from German microdata

Germans are still very fond of using cash. Of all direct payment transactions, cash accounts for an astounding 82% in terms of number, and for 58% in terms of value. With a new and unique dataset that combines transaction information with survey data on payment behaviour of German consumers, we shed light on how individuals choose payment instruments and why cash remains so important. We propose a two-stage empirical framework which jointly explains credit card ownership and the use of cash. Our results indicate that the pattern of cash usage is compatible with systematic economic decision making. Consumers decide upon the adoption of payment cards and then use available payment media according to their transaction and personal characteristics, the relative costs of cash and card usage, and their assessment of payment instruments' characteristics. Whereas older consumers use significantly more cash, the comparison with younger consumers shows that the difference in payment behaviour is not explained by age as such but to a large extent by differences in the characteristics of these two groups. It is interesting that the possession of a credit card, especially alongside a debit card, does not significantly affect the use of cash in Germany. --Payment instruments,payment cards,payment behaviour,payment innovation,cash usage,cash substitution,debit cards,credit cards,survey data

Snakes and ladders in an inhomogeneous neural field model

Continuous neural field models with inhomogeneous synaptic connectivities are known to support traveling fronts as well as stable bumps of localized activity. We analyze stationary localized structures in a neural field model with periodic modulation of the synaptic connectivity kernel and find that they are arranged in a snakes-and-ladders bifurcation structure. In the case of Heaviside firing rates, we construct analytically symmetric and asymmetric states and hence derive closed-form expressions for the corresponding bifurcation diagrams. We show that the ideas proposed by Beck and co-workers to analyze snaking solutions to the Swift--Hohenberg equation remain valid for the neural field model, even though the corresponding spatial-dynamical formulation is non-autonomous. We investigate how the modulation amplitude affects the bifurcation structure and compare numerical calculations for steep sigmoidal firing rates with analytic predictions valid in the Heaviside limit