CFP and YFP photostabilities are differentially affected by common mounting fluids

The use of spectrally distinct variants of green fluorescent protein (GFP) such as cyan or yellow mutants (CFP and YFP, respectively) is very common in all different fields of life sciences, e.g. for marking and tracing of specific proteins or cells or to determine protein interactions. In the later case, the quantum physical phenomenon of fluorescence resonance energy transfer (FRET) is visualized by specific microscopy techniques. When we applied a commonly used FRET microscopy technique - the increase in CFP-fluorescence after bleaching of YFP, we noticed that it worked well for live cells, but that most of the FRET-signal was lost in fixed cells mounted in commercial microscopy mounting fluids. Subsequently, we could show that CFP bleached much faster in the mounting medium than in live cells, while the opposite effect was observed for YFP. This change in photostability was not caused by the fixation but directly dependent on the mounting fluid. Furthermore we made the interesting observation that the CFP-fluorescence intensity increased in live cells after illumination at the YFP-excitation wavelength – a phenomenon, which might cause a false-positive signal in the FRET-microscopy technique that is based on bleaching of YFP. All together our results show that it is problematic to use commercially available mounting fluids for fluorescent proteins due to their differential effects on the bleaching kinetics and that the FRET microscopy technique based on bleaching of the acceptor is prone to artefacts at least for the CFP/YFP pair

The future of the euro

Euro

Equity financing of the entrepreneurial firm

Equity financing of the entrepreneurial firm has achieved a rapid increase over the past> decade. Venture capital funds, which finance privately held start-ups, raised a record $92.3 billion in 2000. This is a 30-fold increase relative to 1990. At Nasdaq, initial public offerings raised an all-time high of$53.6 billion in 2000, which is 24 times as much as in 1990. This article studies venture equity financing and equity financing through initial public offerings against the background of asymmetric information between the entrepreneur and the (outside) investor. The analysis shows that venture capital financing (i) is superior to initial public offerings when the entrepreneur has low initial wealth relative to the size of the project and (ii) is equivalent otherwise. This result highlights the importance of private equity in financing entrepreneurial enterprises. The Gramm-Leach-Bliley Act of 1999 allows banks to expand the scope of their activities in this arena. The act allows financial holding companies to provide equity financing to nonfinancial enterprises for up to ten years. In particular, the act defines a framework in which financial holding companies can sponsor private equity funds that may provide venture capital to entrepreneurial start-ups.Corporations - Finance ; Gramm-Leach-Bliley Act ; Venture capital

Quality spreads in the bond market

Bonds ; Corporate bonds ; Government securities

Gambler’s fallacy?

Stock market

Spinor solution of the sound wave problem

Spinor solution of sound wave in electrically neutral ga

The Tobin tax

Taxation ; Foreign exchange

Stock return and interest rate risk at Fannie Mae and Freddie Mac

Fannie Mae and Freddie Mac are government-sponsored enterprises (GSEs) with the stated objective of promoting home ownership by improving the availability of mortgage financing for private households. These enterprises engage in two separate and distinct lines of business: (i) assembling and marketing pools of mortgages on which they guarantee the timely payments of principal and interest and (ii) purchasing mortgage assets for their own portfolio, mostly funded with debt securities. This article examines the sensitivity of the returns on GSEs' equity shares to realizations of interest rate risk. The study shows that the market value of Fannie Mae's and Freddie Mac's equity is vulnerable to increases in short-term interest rates and changes in the term spread (the difference between the long-term and short-term interest rates).Stock market ; Government-sponsored enterprises ; Mortgage loans

THE SPARTAN SCHOOL OF INSTITUTIONAL ECONOMICS AT MICHIGAN STATE UNIVERSITY

Heterodox scholarship at Michigan State University (MSU) was influenced by the institutional economics of John R. Commons at Wisconsin. But it was far from monolithic and had many other sources and originality of its own. A case can be made that the center of institutional economics moved across Lake Michigan from Madison to East Lansing and blossomed in the second half of the 20th century with such Wisconsin Ph.D's as Raleigh Barlowe, Warren Samuels, Allan Schmid, Harry Trebing, and others. Equally important in making MSU a center of institutional economics were scholars from other institutional backgrounds such as Paul Strassmann, economic development; Robert Solo, science and technology; James Shaffer, agricultural marketing and consumer behavior; Nicholas Mercuro, law and economics; and others.Institutional and Behavioral Economics,