Preequilibrium Neutron Emission in (p, xn) Reactions with 80-160 MeV Projectiles

This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440

Why Don’t People Pay Attention? Endogenous Sticky Information in a DSGE Model

Building on the models of sticky information, we endogenize the probability of obtaining new information by introducing a switching mechanism allowing agents to choose between costly rational expectations and costless expectations under sticky information. Thereby, the share of agents with rational expectations becomes endogenous and timevarying. While central results of sticky information models are retained, we find that the share of rational expectations is positively correlated with the variance of the variable forecasted, providing a link to models of near-rationality. Output expectations in our model are generally more rational than inflation expectations, but the share of rational inflation expectations increases with a rising variance of the interest rate. With regard to optimal monetary policy, we find that the Taylor principle provides a necessary and sufficient condition for the determinacy of the model. However, output and inflation stability are optimized if the central bank does not react too strongly to inflation, but rather also targets the output gap with a relatively large coefficient in the Taylor rule

Sheddable Coatings for Long-Circulating Nanoparticles

Nanoparticles, such as liposomes, polymeric micelles, lipoplexes and polyplexes are frequently studied as targeted drug carrier systems. The ability of these particles to circulate in the bloodstream for a prolonged period of time is often a prerequisite for successful targeted delivery. To achieve this, hydrophilic ‘stealth’ polymers, such as poly(ethylene glycol) (PEG), are used as coating materials. Such polymers shield the particle surface and thereby reduce opsonization by blood proteins and uptake by macrophages of the mononuclear phagocyte system. Yet, after localizing in the pathological site, nanoparticles should deliver their contents in an efficient manner to achieve a sufficient therapeutic response. The polymer coating, however, may hinder drug release and target cell interaction and can therefore be an obstacle in the realization of the therapeutic response. Attempts have been made to enhance the therapeutic efficacy of sterically stabilized nanoparticles by means of shedding, i.e. a loss of the coating after arrival at the target site. Such an ‘unmasking’ process may facilitate drug release and/or target cell interaction processes. This review presents an overview of the literature regarding different shedding strategies that have been investigated for the preparation of sterically stabilized nanoparticulates. Detach mechanisms and stimuli that have been used are described

Demographic Change and R&D-Based Economic Growth: Reconciling Theory and Evidence

In recent decades, most industrialized countries experienced declining population growth rates caused by declining fertility and associated with rising life expectancy. We analyze the effect of continuing demographic change on medium- and long-run economic growth by setting forth an R&D-based growth model including an analytically tractable demographic structure. Our results show that, in response to demographic change, technological progress and economic growth accelerate in the medium run but slow down in the long run. Numerical investigation reveals that the time period during which technological progress and economic growth are faster than without demographic change can be very long. Since the theoretical predictions for the medium run are consistent with the negative association between population growth and economic growth found in the empirical literature, the present framework can reconcile R&D-based growth theory with the available empirical evidence