Domain wall dynamics of the Ising chains in a transverse field

We show that the dynamics of an Ising spin chain in a transverse field conserves the number of domains (strings of down spins in an up-spin background) at discrete times. This enables the determination of the eigenfunctions of the time-evolution operator, and the dynamics of initial states with domains. The transverse magnetization is shown to be identically zero in all sectors with a fixed number of domains. For an initial state with a single string of down spins, the local magnetization, the equal-time and double-time spin-spin correlation functions, are calculated analytically as functions of time and the initial string size. The domain size distribution function can be expressed as a simple integral involving Bessel functions.Comment: 4 pages with three figure

The Last Great Arbitrage: Exploiting the Buy-and-Hold Mutual Fund Investor

This paper demonstrates that an an institutional feature inherent in a multitude of mutual funds managing billions in assets generates fund NAVs that reflect stale prices. Since, in many cases, investors can trade at these NAVs with little or no transactions costs, there is an obvious trading opportunity. Simple, feasible strategies generate Sharpe ratios that are sometimes one hundred times greater than the Sharpe ratio of the underlying fund. These opportunities are especially prevalent in international funds that buy Japanese or European equities and in funds that invest in thinly traded securities in the U.S. When implemented, the gains from these strategies are matched by o setting losses incurred by buy-and-hold investors in these funds. In one particular example, we explore the consequences of trading between different Vanguard mutual funds, motivated via the rules inherent in University 403B plans. Compared to an equal-weighted buy-and-hold portfolio of international Vanguard funds with a 25% cumulative return, the strategy discussed in this paper produces a 139% return while being in the stock market less than 25% of the time

Enhanced photocatalytic and antibacterial activity of plasma-reduced silver nanoparticles

A non-thermal atmospheric pressure plasma jet has been used for the green synthesis of highly dispersed colloidal silver nanoparticles. The reducing species such as hydrogen radicals and hydrated electrons are identified, and the change in the solution pH is studied during AgNP formation. The structural properties and size of the plasma-reduced silver nanoparticles are characterized via X-ray diffraction, ultraviolet-visible spectroscopy, fluorescence spectroscopy and transmission electron microscopy. The size of the colloidal AgNPs is tuned by adjusting the initial concentration of AgNO3. The effect of terephthalic acid, a hydroxyl radical scavenger, on the reduction of Ag+ ion is studied. The typical catalytic activity data indicate the better performance of the plasma-reduced colloidal Ag nanoparticles than that obtained from the chemical reduction method. The antibacterial activity of the plasma-reduced Ag nanoparticles also shows a better performance than that of the chemically reduced AgNPs, highlighting the potential of the plasma reduction approach for the synthesis of metal nanoparticles, which are stable even after 30 days without a stabilizing agent. Additionally, the effects of hydroxyl scavengers (isopropyl alcohol) and Fenton's reagent (Fe2+ salt) on CV degradation are studied

Parasitic flowering plants

Alectra vogelii Benth. (Scrophulariacee) is a root parasite of peanut and several other leguminous crop olants. It has been reported in various countries in Africa (Angola, Burkina Faso, Malawi, Mozambique, Nigeria, Swaziland, Zambia, and Zimbabwe)..

Olpidium root discoloration

Root discoloration of peanut caused by Olpidum brassicae has been reported in the Indian states of Andhra Pradesh, Gujarat, and Punjab and in Texas in the United States..

Rust

Rust is an economically important disease in most peanut producing countries of the world and causes substantial yield losses, particularly if the crop is also attacked by the leaf spot pathogens Cercospora arachidicola and Cercosporidium personatum..

New Groundnut Released in Malawi

About 18% of Malawi's groundnut area is covered with 1CRISAT/DARTS developed improved varieties. With the recent releases (two in 2000 and one in 2001), and available funds from the ICRISAT/USAID Project for seed multiplication, the area under improved varieties will further increase. About US$ 0.35 million may be generated for groundnut seed production during 2001 through the revolving fund