We have benefitted from discussions with Ariel Burstein, Ricardo Caballero, V.V. Chari, Larry Christiano, Larry Jones, Boyan Jovanovic, Patrick Kehoe, Timothy Kehoe, Bob King, Pete Klenow, Oleksiy Kryvtsov, Ellen McGrattan, Thomas Philippon, Thomas Sargent, Nancy Stokey, Julia Thomas, and Aleh Tsyvinski. Participants in seminars at Chicago, Minnesota, the Federal Reserve Bank of Minneapolis, th...

In this paper I show that the standard model of entrepreneurship with borrowing constraints (e.g. Evans and Jovanovic (1989)) embedded in an optimal savings problem predicts that the transition to entrepreneurship as a function of current wealth is ...rst increasing and eventually decreasing. This has important implications for the interpretation of reduced form estimates of the e¤ect of wealth...

abstract phosphorus (p) sorption in soils is a key process governing the availability of p to crops. p sorption characteristics and their relationship to soil properties were determined in twenty-one paired surface soil samples (21 cultivated and 21 adjacent virgin soils) belonging to five soil types: typic calcixerepts, typic haploxerepts, typic endoaquepts, vertic endoaquepts, and vertic calc...

considering the point that the existence of heavy metals in the wastewater are so dangerous forthe environment and it would have many bad consequences for all the creatures including human beings, wemust try out the ways that make us capable of adsorbing these heavy metals. in order to accomplish this goal we should use a method called adsorbing. in this study the adsorption of copper ions in h...

in this study caulerpa racemosa has been characterized and used for the removal of cd(ii) and pb (ii) from aqueous solutions. the effect of ph, adsorbent dosage, contact time and temperature on adsorption process was studied in batch experiments. langmuir and freundlich models were applied to describe the biosorption isotherm of the metal ions by c. racemosa biomass. the adsorption data can be ...

Expert systems have been applied to many areas of research to handle problems effectively. Designing and implementing an expert system is a difficult job, and it usually takes experimentation and experience to achieve high performance. The important feature of an expert system is that it should be easy to modify. They evolve gradually. This evolutionary or incremental development technique has ...

.37. Boileau C, Martel-Pelletier J, Brunet J, et al. Oral treatment with PD-0200347, anα2δ ligand, reduces the development ofexperimental osteoarthritis by inhibiting metalloproteinases and inducible nitric oxide synthase gene expression and synthesis in cartilage chondrocytes. Arthritis Rheum. 2005 Feb;52(2):488-500.38. Pelletier JP, Lascau-Coman V, Jovanovic D, et al. Selectiv...