Hamiltonian formulation of SL(3) Ur-KdV equation

We give a unified view of the relation between the $SL(2)$ KdV, the mKdV, and the Ur-KdV equations through the Fr\'{e}chet derivatives and their inverses. For this we introduce a new procedure of obtaining the Ur-KdV equation, where we require that it has no non-local operators. We extend this method to the $SL(3)$ KdV equation, i.e., Boussinesq(Bsq) equation and obtain the hamiltonian structure of Ur-Bsq equationin a simple form. In particular, we explicitly construct the hamiltonian operator of the Ur-Bsq system which defines the poisson structure of the system, through the Fr\'{e}chet derivative and its inverse.Comment: 12 pages, KHTP-93-03 SNUTP-93-2

The Paraldor Project

Paraldor is an experiment in bringing the power of categorical languages to lattice QCD computations. Our target language is Aldor, which allows the capture of the mathematical structure of physics directly in the structure of the code using the concepts of categories, domains and their inter-relationships in a way which is not otherwise possible with current popular languages such as Fortran, C, C++ or Java. By writing high level physics code portably in Aldor, and implementing switchable machine dependent high performance back-ends in C or assembler, we gain all the power of categorical languages such as modularity, portability, readability and efficiency.Comment: 4 pages, 2 figures, Lattice 2002 conference proceeding

SIRS dynamics on random networks: simulations and analytical models

The standard pair approximation equations (PA) for the Susceptible-Infective-Recovered-Susceptible (SIRS) model of infection spread on a network of homogeneous degree $k$ predict a thin phase of sustained oscillations for parameter values that correspond to diseases that confer long lasting immunity. Here we present a study of the dependence of this oscillatory phase on the parameter $k$ and of its relevance to understand the behaviour of simulations on networks. For $k=4$, we compare the phase diagram of the PA model with the results of simulations on regular random graphs (RRG) of the same degree. We show that for parameter values in the oscillatory phase, and even for large system sizes, the simulations either die out or exhibit damped oscillations, depending on the initial conditions. This failure of the standard PA model to capture the qualitative behaviour of the simulations on large RRGs is currently being investigated.Comment: 6 pages, 3 figures, WIPP to be published in Conference proceedings Complex'2009 February 23-25, Shanghai, Chin

Isoscalar meson spectroscopy from lattice QCD

We extract to high statistical precision an excited spectrum of single-particle isoscalar mesons using lattice QCD, including states of high spin and, for the first time, light exotic JPC isoscalars. The use of a novel quark field construction has enabled us to overcome the long-standing challenge of efficiently including quark-annihilation contributions. Hidden-flavor mixing angles are extracted and while most states are found to be close to ideally flavor mixed, there are examples of large mixing in the pseudoscalar and axial sectors in line with experiment. The exotic JPC isoscalar states appear at a mass scale comparable to the exotic isovector states.Comment: 4 pages, 4 figure

Patterns of phytoplankton productivity in two morphologically different oxbow lakes in the Black Warrior River drainage in Alabama, U.S.A.

Many different types of oxbow lakes, created by river meandering, exist in the drainage of the Black Warrior River. Phytoplankton productivity and spatial distribution of productivity using the ¹⁴C method were studied in two morphologically different oxbow lakes. Touson Lake is a typical oxbow lake type in the region with steep basin morphometry, length (1): 1.2 km, maximum depth (Zm): 6.7 m. Cypress Pond has shallow depth and well-developed submersed aquatic plants, I: 2.25 km, Zm: 2.2 m. Daily production at Touson Lake ranged from 43 to 550 mgC/m²/day (mean: 258, n=6), while Cypress Pond showed somewhat lower productivities (range: 16 to 256 mgC/m²/day, mean: 88, n=4). In highly turbid Touson Lake, highest productivities usually occurred at the surface. In Cypress Pond productivity, which was inhibited at the surface by light, was highest at the 0.5 m depth. Spatial distribution of productivity at Touson Lake was not variable among the 5 sites (19.86 ± 6.6 mgC/m³/h, n=5). However, highly variable distributions of productivity occurred in Cypress Pond (16.51 ± 19.1 mgC/m³/h, n=6). This variability was partly supported by fluctuating underwater light conditions caused by the distribution of submersed aquatic plants. Based on phytoplankton productivity, Touson Lake and Cypress Pond appear to belong to the mesotrophic and oligotrophic lake categories, respectively.Article信州大学理学部付属諏訪臨湖実験所報告 7: 81-90(1991)departmental bulletin pape

Computerized Response Inhibition Training For Children With Trichotillomania

Evidence suggests that trichotillomania is characterized by impairment in response inhibition, which is the ability to suppress pre-potent/dominant but inappropriate responses. This study sought to test the feasibility of computerized response inhibition training for children with trichotillomania. Twenty-two children were randomized to the 8-session response inhibition training (RIT; n = 12) or a waitlisted control (WLT; n = 10). Primary outcomes were assessed by an independent evaluator, using the Clinical Global Impression-Improvement (CGI-I), and the NIMH Trichotillomania Severity (NIMH-TSS) and Impairment scales (NIMH-TIS) at pre, post-training/waiting, and 1-month follow-up. Relative to the WLT group, the RIT group showed a higher response rate (55% vs. 11%) on the CGI-I and a lower level of impairment on the NIMH-TIS, at post-training. Overall symptom reductions rates on the NIMH-TSS were 34% (RIT) vs. 21% (WLT) at post-training. The RIT\u27s therapeutic gains were maintained at 1-month follow-up, as indicated by the CGI-I responder status (= 66%), and a continuing reduction in symptom on the NIMH-TSS. This pattern of findings was also replicated by the 6 waitlisted children who received the same RIT intervention after post-waiting assessment. Results suggest that computerized RIT may be a potentially useful intervention for trichotillomania

A novel quark-field creation operator construction for hadronic physics in lattice QCD

A new quark-field smearing algorithm is defined which enables efficient calculations of a broad range of hadron correlation functions. The technique applies a low-rank operator to define smooth fields that are to be used in hadron creation operators. The resulting space of smooth fields is small enough that all elements of the reduced quark propagator can be computed exactly at reasonable computational cost. Correlations between arbitrary sources, including multi hadron operators can be computed a posteriori without requiring new lattice Dirac operator inversions. The method is tested on realistic lattice sizes with light dynamical quarks.Comment: 14 pages, 9 figure