The Greek Model of the European System of Central Banks Multi-Country Model

The present paper presents a quarterly econometric model for the Greek economy, the GR-MCM model. The model has been developed as part of a larger project within the European System of Central Banks (ESCB), the Multi-Country Model (MCM). The model combines short-run Keynesian dynamics determined by demand with a neoclassical steady state driven by supply factors. A well-specified long-run supply side is fully and simultaneously estimated. As far as the econometric methodology is concerned, the equilibrium relationships are estimated using cointegration analysis, whereas the dynamic equations are specified as error correction models. Standard simulations result in plausible short to long-run responses to exogenous shocks, thus indicating that the model can be useful for policy analysis experiments.Econometric Modelling; Cointegration Techniques; Simulation Results

Two different methodologies for geoid determination from ground and airborne gravity data

In this study, two methodologies are investigated for geoid determination from ground and airborne gravity data. These two methodologies depend on the downward continuation method used. The first is the inverse Poisson integral; the second is the normal free-air gradient. Each of the two methods requires different treatment of the terrain effects and in turn different approaches to determine the geoid. The two geoid solutions, from ground data, are compared with existing GPS/levelling benchmarks and it is found that the second method gives a better fit due to the bias introduced from the inverse Poisson integral. The same process was applied to the airborne data, but with additional processing, that is the filtering of the terrain effects to preserve the consistency of the data due to the filtering of the airborne data. A study on the effect of filtering was also carried out in this paper and it concluded that filtering the terrain effects has no impact on the geoid. In addition, the airborne data, filtered to three different cut-off frequencies, were used to compute the geoid to investigate the possibility of using the denser data, of lower accuracy, to determine a high-resolution geoid. Even though the data filtered to small cut-off frequency have poorer agreement with the ground data, the geoids computed from the different filtered data is the nearly the sam

Molecular cloning and characterization of the human RNase κ, an ortholog of Cc RNase

A novel protein family, designated hereafter as RNase κ (kappa) family, has been recently introduced with the characterization of the specific Cc RNase, isolated from the insect Ceratitis capitata. The human ortholog of this family consists of 98 amino acids and shares > 98% identity with its mammalian counterparts. This RNase is encoded by a single-copy gene found to be expressed in a wide spectrum of normal and cancer tissues. The cDNA of the human ribonuclease has been isolated and subcloned into a variety of prokaryotic expression vectors, but most efforts to express it caused a severe toxic effect. On the other hand, the expression of the human RNase by the use of the methylotrophic yeast Pichia pastoris system resulted in the production of a highly active recombinant enzyme. Using a 30-mer 5′-end-labeled RNA probe as substrate, the purified enzyme seems to preferentially cleave ApU and ApG phosphodiester bonds, while it hydrolyzes UpU bonds at a lower rate. Based on amino acid sequence alignment and substrate specificity data, as well as the complete resistance of the recombinant protein to the placental ribonuclease inhibitor, we concluded that the human RNase κ is a novel endoribonuclease distinct from other known ribonucleases

Production of Enhanced Beam Halos via Collective Modes and Colored Noise

We investigate how collective modes and colored noise conspire to produce a beam halo with much larger amplitude than could be generated by either phenomenon separately. The collective modes are lowest-order radial eigenmodes calculated self-consistently for a configuration corresponding to a direct-current, cylindrically symmetric, warm-fluid Kapchinskij-Vladimirskij equilibrium. The colored noise arises from unavoidable machine errors and influences the internal space-charge force. Its presence quickly launches statistically rare particles to ever-growing amplitudes by continually kicking them back into phase with the collective-mode oscillations. The halo amplitude is essentially the same for purely radial orbits as for orbits that are initially purely azimuthal; orbital angular momentum has no statistically significant impact. Factors that do have an impact include the amplitudes of the collective modes and the strength and autocorrelation time of the colored noise. The underlying dynamics ensues because the noise breaks the Kolmogorov-Arnol'd-Moser tori that otherwise would confine the beam. These tori are fragile; even very weak noise will eventually break them, though the time scale for their disintegration depends on the noise strength. Both collective modes and noise are therefore centrally important to the dynamics of halo formation in real beams.Comment: For full resolution pictures please go to http://www.nicadd.niu.edu/research/beams