Finite size effects on calorimetric cooperativity of two-state proteins

Finite size effects on the calorimetric cooperatity of the folding-unfolding transition in two-state proteins are considered using the Go lattice models with and without side chains. We show that for models without side chains a dimensionless measure of calorimetric cooperativity kappa2 defined as the ratio of the van't Hoff to calorimetric enthalpy does not depend on the number of amino acids N. The average value of kappa2 is about 3/4 which is lower than the experimental value kappa2=1. For models with side chains kappa2 approaches unity as kappa2 \sim N^mu, where exponent mu=0.17. Above the critical chain length Nc =135 these models can mimic the truly all-or-non folding-unfolding transition.Comment: 3 eps figures. To appear in the special issue of Physica

Optical qubit generation by state truncation using an experimentally feasible scheme

Generation of arbitrary superposition of vacuum and one-photon states using quantum scissors device (QSD) is studied. The device allows the preparation of states by truncating an input coherent light. Optimum values of the intensity of the coherent light for the generation of any desired state using the experimentally feasible QSD scheme are found.Comment: 8 pages, 4 figure

Size management by European private firms to minimize proprietary costs of disclosure

We examine size management by European private firms for which disclosure requirements increase at size thresholds. Our estimates suggest at least 8% of firms near thresholds that impose income statement disclosure manage size downward, and the average firm that manages size sacrifices more than 6% of its assets. We find that multiple determinants of proprietary costs predict this behavior, and that size management to avoid mandatory audits, which are similarly imposed at size thresholds, is of comparable magnitude. Our results triangulate the economic significance of proprietary costs in a setting largely without confounding capital market, agency, or compliance costs

Comparing numerical methods for the solutions of systems of ordinary differential equations

AbstractIn this article, we implement a relatively new numerical technique, the Adomian decomposition method, for solving linear and nonlinear systems of ordinary differential equations. The method in applied mathematics can be an effective procedure to obtain analytic and approximate solutions for different types of operator equations. In this scheme, the solution takes the form of a convergent power series with easily computable components. This paper will present a numerical comparison between the Adomian decomposition and a conventional method such as the fourth-order Runge-Kutta method for solving systems of ordinary differential equations. The numerical results demonstrate that the new method is quite accurate and readily implemented

Stabilization of Extra Dimensions at Tree Level

By considering the effects of string winding and momentum modes on a time dependent background, we find a method by which six compact dimensions become stabilized naturally at the self-dual radius while three dimensions grow large.Comment: 15 pages, 2 figures, minor typos correcte

All the World Wide Web's a Stage: Improving students' information skills with dramatic video tutorials

Cataloged from PDF version of article.Purpose – The purpose of this article is to describe a collaborative project organised by Bilkent University Library, Turkey, to produce a series of instructional videos that are both informative and entertaining and also serve to market the library. Design/methodology/approach – The paper will outline the theoretical basis for the use of videos for library instruction, especially with reference to the habits and preferences of so-called Generation Y students and to the potential value of video for facilitating memory and learning. Findings – The use of humorous and interesting content, in a dramatised style, were found to improve Generation Y students’ learning and enjoyment of instructional videos. Practical implications – The development of the project demonstrates the practical and marketing benefits of collaboration by academic librarians with students and faculty. However, it proved more difficult to evaluate the efficiency of the final product in terms of influencing the attitude of students toward the library and library resources and thereby changing their behaviour when studying. Originality/value – The authors recommend that such library videos should definitely form part of an academic library’s information literacy programme, but should not constitute the sole element

Evidence for a Mid-Atomic-Number Atmosphere in the Neutron Star 1E1207.4-5209

Recently Sanwal et al. (2002) reported the first clear detection of absorption features in an isolated neutron star, 1E1207.4-5209. Remarkably their spectral modeling demonstrates that the atmosphere cannot be Hydrogen. They speculated that the neutron star atmosphere is indicative of ionized Helium in an ultra-strong (~1.5x10^{14} G) magnetic field. We have applied our recently developed atomic model (Mori & Hailey 2002) for strongly-magnetized neutron star atmospheres to this problem. We find that this model, along with some simp le atomic physics arguments, severely constrains the possible composition of the atmosphere. In particular we find that the absorption features are naturally associated with He-like Oxygen or Neon in a magnetic field of ~10^{12} G, comparable to the magnetic field derived from the spin parameters of the neutron star. This interpretation is consistent with the relative line strengths and widths and is robust. Our model predicts possible substructure in the spectral features, which has now been reported by XMM-Newton (Mereghetti et al. 2002). However we show the Mereghetti et al. claim that the atmosphere is Iron or some comparable high-Z element at ~ 10^{12} G is easily ruled out by the Chandra and XMM-Newton data.Comment: 5 pages, AASTeX, Revised version. Accepted for publication in ApJ Letter

Treatment of Vegetable Oil Refining Wastes

The common vegetable oils are soybean, sesame, sunflower, corn, canola, and cotton seeds. Their yields, compositions and physical and chemical properties determine their usefulness in various applications aside edible uses. Crude oils obtained by pressing of such vegetable seeds are not usually considered to be edible before the removal of various nonglyceride compounds through operations known as refining. The refining processes remove undesirable materials such as phospholipids, monoacylglycerols, diacylglycerols, free fatty acids, colour and pigments, oxidised materials, etc., but, may also remove valuable minor components such as antioxidants and vitamins (carotenes and tocopherols). The major steps involved in chemical refining include degumming, neutralizing, bleaching, and deodorizing which are the main sources of the effluent. The chapter covers refining steps, its environmental impacts, waste characterization, source reduction, recovery and treatment technologies