DNA electrophoresis studied with the cage model

The cage model for polymer reptation, proposed by Evans and Edwards, and its recent extension to model DNA electrophoresis, are studied by numerically exact computation of the drift velocities for polymers with a length L of up to 15 monomers. The computations show the Nernst-Einstein regime (v ~ E) followed by a regime where the velocity decreases exponentially with the applied electric field strength. In agreement with de Gennes' reptation arguments, we find that asymptotically for large polymers the diffusion coefficient D decreases quadratically with polymer length; for the cage model, the proportionality coefficient is DL^2=0.175(2). Additionally we find that the leading correction term for finite polymer lengths scales as N^{-1/2}, where N=L-1 is the number of bonds.Comment: LaTeX (cjour.cls), 15 pages, 6 figures, added correctness proof of kink representation approac

An empirical test of Holmstroem's principal-agent model that takes tax and signally hypotheses explicitly into account

Management;Incentives;labour economics

Are managers indeed motivated by their bonuses?

Management;Incentives;labour economics

The repton model of gel electrophoresis

We discuss the repton model of agarose gel electrophoresis of DNA. We review previous results, both analytic and numerical, as well as presenting a new numerical algorithm for the efficient simulation of the model, and suggesting a new approach to the model's analytic solution.Comment: 17 pages including 6 PostScript figures, typeset with LaTeX 2e using the Elsevier macro package elsart.cl

Can agriculture end its slump in 2000

Agriculture ; Agricultural productivity

The rural economy in a new century : discussion

Rural areas ; Rural development

Tenth District economic developments

The Tenth District economy posted a healthy gain in 1995, although growth slowed from the vigorous tempo of the year before. The district slowed sharply in the spring, but activity rebounded somewhat later in the year, in a pattern similar to that in the national economy. The district's main economic engines in 1994--construction, manufacturing, trade, and services--downshifted to a more moderate pace of growth in 1995. Activity in the district's energy industry remained sluggish, due to weak prices for crude oil and natural gas; and financial losses in the cattle industry held down the income of district farmers, despite a surge in crop prices.> Growth varied widely across the district. New Mexico was again the star performer, leading the district for the second consecutive year. Growth in Oklahoma, Kansas, and Colorado also was strong, while growth in Missouri, Nebraska, and Wyoming was more moderate.> Barkema reviews developments in the district economy. The outlook for 1996 points to continued moderate growth, probably slightly below the 1995 pace. The economy's healthy tone overall should support further modest gains in services and trade. Activity in the construction industry may rebound slightly from the slowdown in 1995, with a modest recovery in homebuilding and a steady pace of commercial and public works projects. Manufacturing activity may slip somewhat, as the mountain states' industrial expansion slows. Flat energy prices, however, are unlikely to encourage much exploration and drilling activity in the district's energy industry. For the district's farm economy, higher crop prices brighten the outlook, even though the profit picture for the cattle industry remains relatively bleak.Economic development ; Federal Reserve District, 10th

Ag biotech : bold new promise or bold new risk?

Agriculture ; Biotechnology

U.S. agriculture's trade prospects

Agriculture ; Farm produce ; Exports ; International trade

The farm slump continues

The century's final year was one of frustration for U.S. agriculture - certainly not the way the industry had hoped to close the millennium. Farmers took pride> in their productivity, turning out the fourth bin-busting crop in a row and more red meat and poultry than ever before. But the big production collided with a still sluggish world market, holding down farm commodity prices. Still, farm income held up well above the average for the past decade, due to another big financial assistance package from Washington.> The farm slump will likely continue in the year ahead, although prospects for livestock and crop producers diverge widely. Livestock producers could have a very good year, with low feed costs and robust consumer demand boosting profits, but weak crop prices could drag down farm income. The farm export picture is beginning to brighten again, but too gradually to offer much relief in 2000. With exports soft and the nation's granaries still full, weak crop prices could be the norm. As in the last two years, help from Washington may determine whether farm income in 2000 rises or falls.Farm income ; Agricultural productivity ; Agricultural prices