Energy Biased Technical Change: A CGE Analysis

This paper studies energy bias in technical change. For this purpose, we develop a computable general equilibrium model that builds on endogenous growth models. The model explicitly captures links between energy, the rate and direction of technical change, and the economy. We derive the equilibrium determinants of biased technical change and show the importance of feedback in technical change, substitution possibilities between final goods, and generalequilibrium effects for the equilibrium bias. If the feedback effect is strong, or the substitution elasticity large, or both, our model tends to a corner solution in which only technologies are developed that are appropriate for production of non-energy intensive goods. --computable general-equilibrium models,endogenous technical change,energy,environment

Magnitude estimation of perceived distance over various distance ranges

Magnitude estimation judgments of perceived distance for stationary space vehicle under conditions simulating outer spac

A Village-Up View of Sierra Leone’s Civil War and Reconstruction: Multilayered and Networked Governance

Sierra Leone not only has a direct relationship with its citizens as individuals but also a mediated one through the rural governance systems that pre-dated colonialism and often have greater legitimacy than the central state itself. The impact of the civil war in the rural areas was devastating. Nonetheless the pre-war (traditional) leadership structures continued informally to provide whatever degree of governance response was possible. In the 38 communities visited throughout rural Sierra Leone, a third of the chiefs remained with their people (even if in hiding) throughout even the most difficult part of the civil war and most of the rest fled only briefly. During the war chiefs made a major change to include youth and women in their governance practices and this more participatory approach to governance has persisted. Although a large number of chiefs died during the war period, their positions were easily refilled afterward. During the war most communities in the South and East created local Civilommunity Defensce Forces (CDF) to defend themselves. Chiefs retained at least some degree of direction over 71% per cent of the CDF forces in the areas visited, with the consequence that only a third of these CDFs gave trouble to their communities. The role of international donors increased significantly as a result of the war as well. Nonetheless, their initiatives have strengthened, not threatened the legitimacy of the state because the army, police and health services have improved and as local citizens do not know how to access the donors directly they tend to credit their activities to various government actors. The various reforms that have come in the wake of the civil war are incomplete and the institutional boundaries of the newly reconstructed multi-layered governance system are unclear. Not enough attention has been paid to governance at the ‘periphery’.The report was produced under the auspices of the RCUK Global Uncertainties Programme on Security in an Africa of Networked, Multi-Level Governance

Verbal estimation of distance in a simulated space environment

Human performance in estimating distances in simulated space environmen

Tests and comparisons of satellite derived geoids with Skylab altimeter data

The SKYLAB-193 radar altimeter was operated nearly continuously around the world on January 31, 1974. This direct measurement of the sea surface topography provided an independent basis for the evaluation of global geoids computed from satellite derived gravity models. The differences between the altimeter geoid and the satellite geoids were as large as 25 meters with rms values ranging from 8 to 10 meters. These differences also indicated a systematic long wavelength variation (approximately 100 deg) not related to error in the SKYLAB orbits. Truncation of the models to degree and order eight did not eliminate the long wavelength variation, but in every case the rms agreement between satellite and altimeter geoids was improved. Orbits computed with the truncated models were in contrast found to be inferior to those computed using the complete models

Lattice model study of the thermodynamic interplay of polymer crystallization and liquid-liquid demixing

We report Monte Carlo simulations of a lattice-polymer model that can account for both polymer crystallization and liquid-liquid demixing in solutions of semiflexible homopolymers. In our model, neighboring polymer segments can have isotropic interactions that affect demixing, and anisotropic interactions that are responsible for freezing. However, our simulations show that the isotropic interactions also have a noticeable effect on the freezing curve, as do the anisotropic interactions on demixing. As the relative strength of the isotropic interactions is reduced, the liquid-liquid demixing transition disappears below the freezing curve. A simple, extended Flory-Huggins theory accounts quite well for the phase behavior observed in the simulations.Comment: Revtex, 7 pages, the content accepted by J. Chem. Phy

A core genetic module : the Mixed Feedback Loop

The so-called Mixed Feedback Loop (MFL) is a small two-gene network where protein A regulates the transcription of protein B and the two proteins form a heterodimer. It has been found to be statistically over-represented in statistical analyses of gene and protein interaction databases and to lie at the core of several computer-generated genetic networks. Here, we propose and mathematically study a model of the MFL and show that, by itself, it can serve both as a bistable switch and as a clock (an oscillator) depending on kinetic parameters. The MFL phase diagram as well as a detailed description of the nonlinear oscillation regime are presented and some biological examples are discussed. The results emphasize the role of protein interactions in the function of genetic modules and the usefulness of modelling RNA dynamics explicitly.Comment: To be published in Physical Review

Effect of picosecond strain pulses on thin layers of the ferromagnetic semiconductor (Ga,Mn)(As,P)

The effect of picosecond acoustic strain pulses (ps-ASP) on a thin layer of (Ga,Mn)As co-doped with phosphorus was probed using magneto-optical Kerr effect (MOKE). A transient MOKE signal followed by low amplitude oscillations was evidenced, with a strong dependence on applied magnetic field, temperature and ps-ASP amplitude. Careful interferometric measurement of the layer's thickness variation induced by the ps-ASP allowed us to model very accurately the resulting signal, and interpret it as the strain modulated reflectivity (differing for $\sigma_{\pm}$ probe polarizations), independently from dynamic magnetization effects.Comment: 6 pages, 5 figure