A SPATIAL MODEL OF REGIONAL VARIATIONS IN EMPLOYMENT GROWTH IN APPALACHIA

In this study, a spatial equilibrium model of employment growth is developed and empirically estimated by Generalized Spatial Two-Stage Least Squares (GS2SLS) estimator using cross-sectional data from Appalachian counties for 1990-2000. Besides the existence of spatial spillover effects, the results suggest that agglomerative effects that arise from the demand and the supply side contribute to employment growth in the study area during the study period. The policy implications of the findings are: (1) Regional cooperation of counties and communities is advisable and may in fact be necessary to design effective policies to encourage employment growth; and (2) Policy makers at the county level may need to design policies that can attract people with high endowments of human capital and higher income into their respective counties.APPALACHIA, EMPLOYMENT GROWTH, SPATIAL MODEL

A Spatial Panel Simultaneous-Equations Model of Business Growth, Migration Behavior, Local Public Services and Household Income in Appalachia

In this paper we develop a spatial panel simultaneous-equations model of business growth, migration behavior, local public services and median household income in a partial lag-adjustment growth-equilibrium framework and utilizing a one-way error component model for the disturbances. This model is an extension of the jobs follow people or people follow jobs literature and it improved previous models in the growth-equilibrium tradition by: (1) explicitly modeling local government and regional income in the growth process; (2) explicitly modeling gross in-migration and gross out-migration separately in order to spell out the differential effects, which used to be glossed over under net population change in previous studies; (3) explicitly incorporating both spatially lagged dependent variables and spatially lagged error terms to account for spatial spillover effects in the data set; and (4) extending and generalizing the modeling and estimation of simultaneous systems of spatially interrelated cross sectional equations into a panel data setting. To estimate the model, we develop a five-step new estimation strategy by generalizing the Generalized Spatial Three-Stage Least Squares (GS3SLS) approach outlined in Kelejian and Prucha (2004) into a panel data setting. The empirical implementation of the model uses county-level data from the 418 Appalachian counties for 1980-2000. Generally, the results from these model estimations are consistent with the theoretical expectations and empirical findings in the equilibrium growth literature and provide support to the basic hypotheses of this study. First, the estimates show the existence of feedback simultaneities among the endogenous variables of the model. Second, the results also show the existence of conditional convergence with respect to the respective endogenous variable of each equation of the model and the speed of adjustment parameters are generally comparable to those in literature. Third, the results from the parameter estimation of the model indicate the existence of spatial autoregressive lag effects and spatial cross-regressive lag effects with respect to the endogenous variables of the model. One of the key conclusions is that sector specific policies should be integrated and harmonized in order to give the desirable outcome. Besides, regionally focusing resources for development policy may yield greater returns than treating all locations the same.Community/Rural/Urban Development,

Comparison of measured and predicted performance of a SIS waveguide mixer at 345 GHz

The measured gain and noise of a SIS waveguide mixer at 345 GHz have been compared with theoretical values, calculated from the quantum mixer theory using a three port model. As a mixing element, we use a series array of two Nb-Al2O3-Nb SIS junctions. The area of each junction is 0.8 sq microns and the normal state resistance is 52 omega. The embedding impedance of the mixer has been determined from the pumped DC-IV curves of the junction and is compared to results from scale model measurements (105 x). Good agreement was obtained. The measured mixer gain, however, is a factor of 0.45 plus or minus 0.5 lower than the theoretical predicted gain. The measured mixer noise temperature is a factor of 4-5 higher than the calculated one. These discrepancies are independent on pump power and are valid for a broad range of tuning conditions

Apes communicate about absent and displaced objects: methodology matters

Displaced reference is the ability to refer to an item that has been moved (displaced) in space and/or time, and has been called one of the true hallmarks of referential communication. Several studies suggest that nonhuman primates have this capability, but a recent experiment concluded that in a specific situation (absent entities) human infants display displaced reference but chimpanzees do not. Here we show that chimpanzees and bonobos of diverse rearing histories are capable of displaced reference to absent and displaced objects. It is likely that some of the conflicting findings from animal cognition studies are due to relatively minor methodological differences, but are compounded by interpretation errors. Comparative studies are of great importance in elucidating the evolution of human cognition, however, greater care must be taken with methodology and interpretation for these studies to accurately reflect species differences

Preparation of low-sulfur platinum and platinum aluminide layers in thermal barrier coatings

A method for preparing a coated nickel-base superalloy article reduces the sulfur content of the surface region of the metallic coating layers to low levels, thereby improving the adhesion of the coating layers to the article. The method includes depositing a first layer of platinum overlying the surface of a substrate, depositing a second layer of aluminum over the platinum, and final desulfurizing the article by heating the article to elevated temperature, preferably in hydrogen, and removing a small amount of material from the surface that was exposed during the step of heating. A ceramic layer may be deposited over the desulfurized article. The article may also be similarly desulfurized at other points in the fabrication procedure

Performance Characteristics of Nile Tilapia (Oreochromis niloticus) Fed Diets Containing Graded Levels of Fuel-Based Distllers Dried Grains with Solubles

A feeding trial was performed to investigate levels of corn-based Distillers Dried Grains with solubles (DDGS), a co-product of fuel ethanol manufacturing, used as a nutrient source for juvenile Nile tilapia (Oreochromis niloticus). Three isocaloric (15.7±0.7 MJ kg-1 dry matter), isonitrogenous (29.6±1.0% crude protein) experimental diets were formulated to contain 20, 30 and 40% DDGS; a commercial diet containing fishmeal was used as a reference diet. Glass aquaria (110 L) were stocked with Nile tilapia (mean weight = 6.7 g) with four replicates per diet. Weight gains, conversion ratios and hepatosomatic indices did not significantly differ between fish fed 20% DDGS and reference diets. Dressing percentages were similar among fish fed 20 and 30% DDGS and reference diets, while no difference occurred in protein efficiency ratios among diets. These results indicate that aquaculture diets incorporating 20% DDGS may produce similar performance results to commercial diets of similar energy content

Limitations of thermal power plants to solar and wind development in Brazil

Some three fourths of electricity generation in Brazil come from renewables. Most of it is supplied by hydro, complemented by biomass-fueled thermal power plants and wind, while solar is still irrelevant. However, in the medium and long terms, a strong growth is expected for wind and solar in the country. Solar and wind resources are variable in time, partially unpredictable and cannot be dispatched to meet the load. These characteristics require system flexibility, which is the capacity of the power grid to adapt to different supply and demand patterns. Given that most thermal plants are not designed for a large frequency of operating cycles, renewables penetration may result in higher maintenance and operating costs, increased fuel consumption and reduced lifetime. Furthermore, some units might be called out-off-merit to maintain voltage and frequency levels. This paper presents preliminary results on the ability of thermal units to provide flexibility to the country´s grid, through an analysis for the Northeast region bounded by transmission constraints among 65 nodes (out of 196 nodes along the country). Results show that the power sector in Brazil might not be well equipped to deal with high penetration rates of variable renewable energy sources, with impacts on the capacity factor, and on the efficiency, of thermal power plants in the country. They also reveal that while wind energy increases the need of ramping capabilities, solar has greater impacts on the number of starts and shutdowns of conventional units.This research was supported by a Marie Curie International Research Staff Exchange Scheme Fellowship within the 7th European Union Framework Programme, under project NETEP- European Brazilian Network on Energy Planning (PIRSES-GA-2013-612263). The authors would also like to express their gratitude to the Coordination for the Improvement of Higher Education Personnel (CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior) for the essential support given for this work to be carried out