Drinfeld Twists and Algebraic Bethe Ansatz of the Supersymmetric t-J Model

We construct the Drinfeld twists (factorizing $F$-matrices) for the supersymmetric t-J model. Working in the basis provided by the $F$-matrix (i.e. the so-called $F$-basis), we obtain completely symmetric representations of the monodromy matrix and the pseudo-particle creation operators of the model. These enable us to resolve the hierarchy of the nested Bethe vectors for the $gl(2|1)$ invariant t-J model.Comment: 23 pages, no figure, Latex file, minor misprints are correcte

Correlations and Binding in 4D Dynamical Triangulation

We study correlations on the euclidean spacetimes generated in Monte Carlo simulations of the model. In the elongated phase, curvature correlations appear to fall off like a fractional power. Near the transition to the crumpled phase this power is consistent with 4. We also present improved data of our computations of the binding energy of test particles.Comment: 4 pages for proceedings Lattice '95; latex, espcrc2.sty and postscript figure files packed with uufiles; corrected packing, contents of paper unchange

Assessment of Psychophysiological Differences of West Point Cadets and Civilian Controls Immersed within a Virtual Environment

Abstract. An important question for ecologically valid virtual environments is whether cohort characteristics affect immersion. If a method for assessing a cer-tain neurocognitive capacity (e.g. attentional processing) is adapted to a cohort other than the one that was used for the initial normative distribution, data ob-tained in the new cohort may not be reflective of the neurocognitive capacity in question. We assessed the psychophysiological impact of different levels of immersion upon persons from two cohorts: 1) civilian university students; and 2) West Point Cadets. Cadets were found to have diminished startle eyeblink amplitude compared with civilians, which may reflect that cadets experienced less negative affect during the scenario in general. Further, heart rate data re-vealed that Cadets had significantly lower heart rates than Civilians in the “low ” but not “high ” immersion condition. This suggests that “low ” immersion conditions may not have the ecological validity necessary to evoke consistent affect across cohorts

The Economic Value of Fundamental and Technical Information in Emerging Currency Markets

We measure the economic value of information derived from macroeconomic variables and from technical trading rules for emerging markets currency investments. Our analysis is based on a sample of 21 emerging markets with a floating exchange rate regime over the period 1997-2007 and explicitly accounts for trading restrictions on foreign capital movements by using non-deliverable forward data. We document that both types of information can be exploited to implement profitable trading strategies. In line with evidence from surveys of foreign exchange professionals concerning the use of fundamental and technical analysis, we find that combining the two types of information improves the risk-adjusted performance of the investment strategies.emerging markets;foreign exchange rates;heterogeneous agents;technical trading;structural exchange rate models

Investing in the future - identifying participants in an educational program for middle-aged and older adults

With the aging of societies, gerontological issues have become increasingly relevant. Within health education research, however, issues related to aging remain underrepresented. It is not yet understood whether and by what means people prepare for their aging. This article seeks to identify those who invest in the future by examining the reach of the educational program ‘In anticipation of the golden years’. We studied what motivated participants to enroll, and collected demographic, psychological and social network characteristics from the 158 individuals (mean age 61.5 years) who had signed up for the program. These data were compared with data from large-scale surveys of the aging population in order to examine the representativeness of program participants. The majority of participants' motives corresponded very well with the aims of the program. Comparison of demographic, psychological and social characteristics revealed that, in general, participants enjoyed greater psychological resources than in the population, while they were less advantaged with respect to their personal situation (predominantly household composition and subjective health) and social relationships. Our findings suggest that future investment in relation to aging is a well-accepted idea that appeals to individuals who exhibit a specific combination of resources and risk factors

A ``Gaussian'' Approach to Computing Supersymmetric Effective Actions

For nonsupersymmetric theories, the one-loop effective action can be computed via zeta function regularization in terms of the functional trace of the heat kernel associated with the operator which appears in the quadratic part of the action. A method is developed for computing this functional trace by exploiting its similarity to a Gaussian integral. The procedure is extended to superspace, where it is used to compute the low energy effective action obtained by integrating out massive scalar supermultiplets in the presence of a supersymmetric Yang-Mills background.Comment: 17 pages, Latex, elsar

Herpetofauna From An Urban Pampa Fragment In Southern Brazil: Composition, Structure And Conservation

Faunistic inventories regarding natural history of amphibians and reptiles are considered scarce and very little is known about their assemblages in urban areas; the Pampas morphoclimatic domain, also known as Uruguayan Savannah or Southern Grasslands, is also poorly known regarding their faunal composition. Herein, we present a checklist of 16 amphibian and 20 reptile species recorded over a course of four years in the Instituto Federal de Educação, Ciências e Tecnologia, Câmpus Pelotas-Visconde da Graça, in Pelotas, Rio Grande do Sul, Brazil. We also present data on natural history and discuss conservation efforts to be undertaken in the area, in one of the least preserved and known Brazilian morphoclimatic domains, providing insights into urban herpetofaunal diversity patterns and showing the importance of modified areas in its conservation. © 2016 Check List and Authors.12

Spreading Dynamics of Polymer Nanodroplets

The spreading of polymer droplets is studied using molecular dynamics simulations. To study the dynamics of both the precursor foot and the bulk droplet, large drops of ~200,000 monomers are simulated using a bead-spring model for polymers of chain length 10, 20, and 40 monomers per chain. We compare spreading on flat and atomistic surfaces, chain length effects, and different applications of the Langevin and dissipative particle dynamics thermostats. We find diffusive behavior for the precursor foot and good agreement with the molecular kinetic model of droplet spreading using both flat and atomistic surfaces. Despite the large system size and long simulation time relative to previous simulations, we find no evidence of hydrodynamic behavior in the spreading droplet.Comment: Physical Review E 11 pages 10 figure

SISCLIMA : capitalisation de données agroclimatiques au Brésil

Dans le cadre de son système d'informations géographiques sur l'environnement en milieu rural (SISGEO), l'entreprise Brésilienne de Recherches Agronomiques (EMBRAPA) a mis au point un système de capitalisation d'informations agroclimatiques (SISCLIMA). Celui-ci a comme objectif la fourniture automatique des produits les plus classiques dans ce domaine (bulletin météorologique, calculs d'évapotranspiration, etc.), à partir des données brutes collectées sur une station météorologique. Le module comprend une vérification systématique détaillée des données saisies et leur correction, et fournit un fichier opérationnel des données élaborées au niveau journalier. Ce travail rend compte des critères climatologiques adoptés et des méthodes informatiques utilisées pour sa réalisation. (Résumé d'auteur