6,239 research outputs found
Data uncertainty and the role of money as an information variable for monetary policy
This paper shows that money can play an important role as an information variable when initial output data are measured with error and subject to revision. Using an estimated model of the euro area we find that current output estimates may be substantially improved by including money growth in the information set. The gain in precision, however, depends on the magnitude of the output measurement error relative to the money demand shock. We find noticable but small improvements in output estimates, if the uncertainty due to money demand shocks corresponds to the estimated variance obtained from the money demand equation. Money plays a quantitatively more important role with regard to output estimation if we allow for a contribution of monetary analysis in reducing uncertainty due to money demand shocks. In this case, money also helps to reduce uncertainty about output forecasts JEL Classification: E31, E52, E58, E61euro area, Kalman ?lter, macroeconomic modelling, measurement error, monetary policy rules, Rational Expectations
The performance of forecast-based monetary policy rules under model uncertainty
We investigate the performance of forecast-based monetary policy rules using five macroeconomic models that reflect a wide range of views on aggregate dynamics. We identify the key characteristics of rules that are robust to model uncertainty: such rules respond to the one-year ahead inflation forecast and to the current output gap, and incorporate a substantial degree of policy inertia. In contrast, rules with longer forecast horizons are less robust and are prone to generating indeterminacy. In light of these results, we identify a robust benchmark rule that performs very well in all five models over a wide range of policy preferences JEL Classification: E31, E52, E58, E61
An Adaptive Threshold in Mammalian Neocortical Evolution
Expansion of the neocortex is a hallmark of human evolution. However, it
remains an open question what adaptive mechanisms facilitated its expansion.
Here we show, using gyrencephaly index (GI) and other physiological and
life-history data for 102 mammalian species, that gyrencephaly is an ancestral
mammalian trait. We provide evidence that the evolution of a highly folded
neocortex, as observed in humans, requires the traversal of a threshold of 10^9
neurons, and that species above and below the threshold exhibit a bimodal
distribution of physiological and life-history traits, establishing two
phenotypic groups. We identify, using discrete mathematical models,
proliferative divisions of progenitors in the basal compartment of the
developing neocortex as evolutionarily necessary and sufficient for generating
a fourteen-fold increase in daily prenatal neuron production and thus traversal
of the neuronal threshold. We demonstrate that length of neurogenic period,
rather than any novel progenitor-type, is sufficient to distinguish cortical
neuron number between species within the same phenotypic group.Comment: Currently under review; 38 pages, 5 Figures, 13 Supplementary
Figures, 2 Table
Stimulation of phosphatidylinositol 4-phosphate phosphorylation in human placenta membranes by GTPγS
AbstractIn human placenta membranes the rate limiting enzyme for PIP2 formation from PI is PIP kinase. GTPγS is shown to activate PIP kinase by increasing Vmax of the enzyme. It is suggested that a guanine nucleotide regulatory protein is involved in the activation of PIP kinase although coupling with a specific receptor is not yet known. Since PIP2 is the preferred substrate of phospholipase C, the possibility exists that an increase of PIP2 due to activation of PIP kinase leads to an enhancement of phospholipase C activity and hence to an increased production of IP3 and DAG
Data uncertainty and the role of money as an information variable for monetary policy
This paper shows that money can play an important role as an information variable when initial output data are measured with error and subject to revision. Using an estimated model of the euro area we find that current output estimates may be substantially improved by including money growth in the information set. The gain in precision, however, depends on the magnitude of the output measurement error relative to the money demand shock. We find noticable but small improvements in output estimates, if the uncertainty due to money demand shocks corresponds to the estimated variance obtained from the money demand equation. Money plays a quantitatively more important role with regard to output estimation if we allow for a contribution of monetary analysis in reducing uncertainty due to money demand shocks. In this case, money also helps to reduce uncertainty about output forecast
Laminin-1 redistributes postsynaptic proteins and requires rapsyn, tyrosine phosphorylation, and Src and Fyn to stably cluster acetylcholine receptors
Clustering of acetylcholine receptors (AChRs) is a critical step in neuromuscular synaptogenesis, and is induced by agrin and laminin which are thought to act through different signaling mechanisms. We addressed whether laminin redistributes postsynaptic proteins and requires key elements of the agrin signaling pathway to cause AChR aggregation. In myotubes, laminin-1 rearranged dystroglycans and syntrophins into a laminin-like network, whereas inducing AChR-containing clusters of dystrobrevin, utrophin, and, to a marginal degree, MuSK. Laminin-1 also caused extensive coclustering of rapsyn and phosphotyrosine with AChRs, but none of these clusters were observed in rapsyn −/− myotubes. In parallel with clustering, laminin-1 induced tyrosine phosphorylation of AChR β and δ subunits. Staurosporine and herbimycin, inhibitors of tyrosine kinases, prevented laminin-induced AChR phosphorylation and AChR and phosphotyrosine clustering, and caused rapid dispersal of clusters previously induced by laminin-1. Finally, laminin-1 caused normal aggregation of AChRs and phosphotyrosine in myotubes lacking both Src and Fyn kinases, but these clusters dispersed rapidly after laminin withdrawal. Thus, laminin-1 redistributes postsynaptic proteins and, like agrin, requires tyrosine kinases for AChR phosphorylation and clustering, and rapsyn for AChR cluster formation, whereas cluster stabilization depends on Src and Fyn. Therefore, the laminin and agrin signaling pathways overlap intracellularly, which may be important for neuromuscular synapse formation
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