(-)-CGP 12177 causes cardiostimulation and binds to cardiac putative beta 4-adrenoceptors in both wild-type and beta 3-adrenoceptor knockout mice

Some blockers of beta1- and beta2-adrenoceptors cause cardiostimulant effects through an atypical beta-adrenoceptor (putative beta4-adrenoceptor) that resembles the beta3-adrenoceptor. It is likely but not proven that the putative beta4-adrenoceptor is genetically distinct from the beta3-adrenoceptor. We therefore investigated whether or not the cardiac atypical beta-adrenoceptor could mediate agonist effects in mice lacking a functional beta3-adrenoceptor gene (beta3 KO). (-)-CGP 12177, a beta1- and beta2-adrenoceptor blocker that causes agonist effects through both beta3-adrenoceptors and cardiac putative beta4-adrenoceptors, caused cardiostimulant effects that were not different in atria from wild-type (WT) mice and beta3 KO mice. The effects of (-)-CGP 12177 were resistant to blockade by (-)-propranolol (200 nM) but were blocked by (-)-bupranolol (1 microM) with an equilibrium dissociation constant of 15 nM in WT and 17 nM in beta3 KO. (-)-[3H]CGP 12177 labeled a similar density of the putative beta4-adrenoceptor in ventricular membranes from the hearts of both WT (Bmax = 52 fmol/mg protein) and beta3 KO (Bmax = 53 fmol/mg protein) mice. The affinity of (-)-[3H]CGP 12177 for the cardiac putative beta4-adrenoceptor was not different between WT (Kd = 46 nM) and beta3 KO (Kd= 40 nM). These results provide definitive evidence that the cardiac putative beta4-adrenoceptor is distinct from the beta3-adrenoceptor.     

Interregional transfers: A political-economy CGE approach

We model the effects of changes in a federal governments inter-regional transfers within the context of a CGE model of a federal system in which regional governments act to maximise the welfare of the residents of their region subject to the effects of their decision on regional economic outcomes. Regional governments are modelled as players in a non-cooperative game. Simulations are conducted with six versions of a small two-region model, each calibrated for a particular Australian state and the rest of the nation. We show that a change in the level of transfers has little influence on per-capita private consumption, government consumption and welfare, and that its main effect is to induce migration from the donor region to the recipient region.Received: 27 June 2001, Accepted: 20 December 2002, JEL Classification: C72, D58, H73, R13, R23The research reported in this article was supported by a SPIRT Grant from the Australian Research Council. We are indebted to Peter Dixon, James Giesecke, Sang-Hee Han, Peter McGregor, Alex Scherini, two anonymous referees, and the Pacific editor for their valuable comments and suggestions. The usual disclaimer applies.     

The effects of fiscal equalisation in a model with endogenous regional governments: an analysis in a two-region numerical model

This paper is concerned primarily with the economic and welfare consequences of federal redistributive grants. We use a model which has two regions, each with households, firms and regional governments as well as a federal government. Private agents are (utility and profit) maximisers and we assume that regional governments are empire-builders in that they choose their expenditure and tax levels so as to maximise total expenditure—the size of their empire. Labour is free to move between regions in response to utility differences and does so until such differences have been eliminated. Inter-regional migration, inter-regional trade flows and federal government redistribution are the main sources of interconnectedness between the two regions. The model is linearised in log-differences and simulated using a calibration based on Australian state-level data. We find that the welfare effect of intergovernmental transfers is trivial but that all other variables of interest change substantially—consumption, employment, prices, taxes, wages, output and government expenditure. Finally, the signs of the effects of a federal transfer are not affected by the empire-building behaviour of regional governments although the magnitude of the effects is generally dampened.     

Model selection in spatio-temporal electromagnetic source analysis

Several methods [model selection procedures (MSPs)] to determine the number of sources in electroencephalogram (EEG) and magnetoencphalogram (MEG) data have previously been investigated in an instantaneous analysis. In this paper, these MSPs are extended to a spatio-temporal analysis if possible. It is seen that the residual variance (RV) tends to overestimate the number of sources. The Akaike information criterion (AIC) and the Wald test on amplitudes (WA) and the Wald test on locations (WL) have the highest probabilities of selecting the correct number of sources. The WA has the advantage that it offers the opportunity to test which source is active at which time sample.     

The effects of scaffolding metacognitive activities in small groups

This study examined the effects of scaffolds on triads’ metacognitive activities in complex open learning environments. In an experimental design, two experimental groups receiving scaffolds were compared with a control group. The experimental groups differed in the form of scaffolding messages used: structuring scaffolds vs. problematizing scaffolds. We analyzed the effects of scaffolding and the different forms of scaffolds on the amount of metacognitive activities of triads on the interpersonal plane. The results show that scaffolding has a significant effect on stimulating metacognitive activities; triads receiving scaffolds performed significantly more metacognitive activities on the interpersonal plane. Additionally, scaffolding also has a significant development effect; triads continue to show more metacognitive activities after the scaffolding is ceased. Finally, no significant differences between the two forms of scaffolding were found: triads receiving problematizing scaffolds did not showed more metacognitive activities during or after the scaffolding compared to triads receiving structuring scaffolds.