Hedging in Field Theory Models of the Term Structure

We use path integrals to calculate hedge parameters and efficacy of hedging in a quantum field theory generalization of the Heath, Jarrow and Morton (HJM) term structure model which parsimoniously describes the evolution of imperfectly correlated forward rates. We also calculate, within the model specification, the effectiveness of hedging over finite periods of time. We use empirical estimates for the parameters of the model to show that a low dimensional hedge portfolio is quite effective.Comment: 18 figures, Invited Talk, International Econophysics Conference, Bali, 28-31 August 200

The relationship between mental toughness and cognitive control: evidence from the item-method directed forgetting task

Previous research by the authors found that mental toughness, as measured by the Mental Toughness Questionnaire 48 (MTQ48; Clough, P.J., Earle, K., & Sewell, D. [2002]. Mental toughness: the concept and its measurement. In I. Cockerill (Ed.), Solutions in sport psychology [pp. 32–43]. London: Thomson Publishing), was significantly associated with performance on the list-method directed forgetting task. The current study extends this finding to the item-method directed forgetting task in which the instruction to Remember or Forget is given after each item in the study list. A significant positive association was found between the correct recognition of Remember words and the emotional control subscale of the MTQ48. No significant associations were observed with other measures of mental toughness or personality. The findings are discussed in terms of the relationship between mental toughness and cognitive control

Alfalfa Yields from Mixtures of Dormant and Non-dormant Varieties

During the establishment year, alfalfa seedings typically yield only 40-60% of fully established stands. All alfalfa varieties grown in Iowa are classified as dormant or moderately dormant, a characteristic that is important for winter survival. However, as plants become dormant in late summer, their yield declines. Alfalfa varieties from the southwestern United States are non-dormant and continue to grow until the autumn freeze, but tend to die over winter. The objective of this experiment was to determine if including a proportion of non-dormant seed at planting could improve establishment year yield without affecting successive year yields or forage quality. The rationale for this experiment is that more plants are present in the first year of a stand than in successive years when individual plants grow larger as their crowns expand. Because of normal plant loss, we reasoned that death of non-dormant plants after the first winter might not adversely affect the yields of the remaining stand

Theoretical Uncertainties in Red Giant Branch Evolution: The Red Giant Branch Bump

A Monte Carlo simulation exploring uncertainties in standard stellar evolution theory on the red giant branch of metal-poor globular clusters has been conducted. Confidence limits are derived on the absolute V-band magnitude of the bump in the red giant branch luminosity function (M_v,b) and the excess number of stars in thebump, R_b. The analysis takes into account uncertainties in the primordial helium abundance, abundance of alpha-capture elements, radiative and conductive opacities, nuclear reaction rates, neutrino energy losses, the treatments of diffusion and convection, the surface boundary conditions, and color transformations. The uncertainty in theoretical values for the red giant bump magnitude varies with metallicity between +0.13/-0.12 mag at [Fe/H] = -2.4 and +0.23/-0.21 mag at [Fe/H] = -1.0$. The dominant sources of uncertainty are the abundance of the alpha-capture elements, the mixing length, and the low-temperature opacities. The theoretical values of M_v,b are in good agreement with observations. The uncertainty in the theoretical value of R_b is +/-0.01 at all metallicities studied. The dominant sources of uncertainty are the abundance of the alpha-capture elements, the mixing length, and the high-temperature opacities. The median value of R_b varies from 0.44 at [Fe/H] = -2.4$ to 0.50 at [Fe/H] = -1.0. These theoretical values for R_b are in agreement with observations.Comment: 30 pages, 6 figures. To appear in Ap

Virtual volatility

We introduce the concept of virtual volatility. This simple but new measure shows how to quantify the uncertainty in the forecast of the drift component of a random walk. The virtual volatility also is a useful tool in understanding the stochastic process for a given portfolio. In particular, and as an example, we were able to identify mean reversion effect in our portfolio. Finally, we briefly discuss the potential practical effect of the virtual volatility on an investor asset allocation strategy.Comment: 15 pages, 2 figures, elsart.cls, Accepted to Physica A. Added few comments that clarify data used for empirical wor

Doppler-free two-photon spectrum of the 000 band of the Ã1B1←X1A1 transition in difluorodiazirine, F2CN2

The Doppler-free two-photon excitation spectrum of the vibrationless Ã1B1←Image 1A1 transition of difluorodiazirine (F2CN2) has been recorded with a resolution of 15 MHz using a cw single-mode dye laser coupled to an external concentric resonator. The asymmetric rotor spectrum has been analysed and more than 350 lines randomly selected from all five branches were assigned in order to fit the ground- and excited-state rotational and quartic centrifugal distortion constants. From the rotational constants the rNN and rFF distances in the ground Image 1A1 and excited Ã1B1 state were determined. The geometry change upon excitation is found to be ΔrNN = 3.89(2) pm and ΔrFF = −4.09(2) pm. No perturbation in the rotational structure of the 000 band has been found. This points to a small singlet-triplet coupling matrix element in the small molecule limit

Trinity University\u27s Summer Bridge Program: Navigating the Changing Demographics in Higher Education

Our article is divided into five sections. First, our study explores the demographic, economic, and cultural changes influencing higher education. We also explain the tangible and intangible benefits of a college education for first-generation, underrepresented students (FGUS). Second, we provide a brief discussion of the history of Trinity University and our Summer Bridge program. Third, our study describes our Summer Bridge program. Fourth, the data we collected examines how our Summer Bridge students’ grades and retention rates compare to our other first-year students. And, fifth, our article concludes with a discussion of future directions for our Summer Bridge program and how it may apply to other higher educational institutions. In particular, we offer recommendations for other student affairs professionals who also will be experiencing an increase in first-generation, underrepresented students

High-school students' mastery of basic flow-control constructs through the lens of reversibility

High-school students specialising in computing fields need to develop the abstraction skills required to understand and create programs. Novices' difficulties at high-school level, ranging from mastery of the "notional machine"to recognition of a program's purpose, have not been investigated as extensively as at tertiary level. This work explores high-school students' code comprehension by asking to reason about reversing conditional and iteration constructs. A sample of 205 K11 - 13 students from different institutions were asked to engage in a set of "reversibility tasklets". For each code fragment, they need to identify if its computation is reversible and either provide the code to reverse or an example of a value that cannot be reversed. For 4 such items, after extracting the recurrent patterns in students' answers, we have carried out an analysis within the framework of the SOLO taxonomy. Overall, 74% of answers correctly identified if the code was reversible but only 42% could provide the full explanation/code. The rate of relational answers varies from 51% down to 21%, the poorest performance arising for a small array-processing loop (and although 65% of the subjects had correctly identified the loop as reversible). The instruction level did not have a strong impact on performance, indicating such tasks are suitable for K11, when the basic flow-control constructs are usually introduced. In particular, the reversibility concept could be a useful pedagogical instrument both to assess and to help develop students' program comprehension

The ACS LCID project IV: detection of the RGB bump in isolated galaxies of the Local Group

We report the detection and analysis of the red giant branch luminosity function bump in a sample of isolated dwarf galaxies in the Local Group. We have designed a new analysis approach comparing the observed color-magnitude diagrams with theoretical best-fit color-magnitude diagrams derived from precise estimates of the star formation histories of each galaxy. This analysis is based on studying the difference between the V-magnitude of the RGB bump and the horizontal branch at the level of the RR Lyrae instability strip (Delta_vhbb) and we discuss here a technique for reliably measuring this quantity in complex stellar systems. By using this approach, we find that the difference between the observed and predicted values of Delta_vhbb is +0.13 +/- 0.14 mag. This is smaller, by about a factor of two, than the well-known discrepancy between theory and observation at low metallicity commonly derived for Galactic globular clusters. This result is confirmed by a comparison between the adopted theoretical framework and empirical estimates of the Delta_vhbb parameter for both a large database of Galactic globular clusters and for four other dSph galaxies for which this estimate is available in the literature. We also investigate the strength of the red giant branch bump feature (R_bump), and find very good agreement between the observed and theoretically predicted R_bump values. This agreement supports the reliability of the evolutionary lifetimes predicted by theoretical models of the evolution of low-mass stars.Comment: Accepted for publication on Ap