Comparison of Some Exact and Perturbative Results for a Supersymmetric SU(NcN_c) Gauge Theory

We consider vectorial, asymptotically free ${\cal N}=1$ supersymmetric SU($N_c$) gauge theories with $N_f$ copies of massless chiral super fields in various representations and study how perturbative predictions for the lower boundary of the infrared conformal phase, as a function of $N_f$, compare with exact results. We make use of two-loop and three-loop calculations of the beta function and anomalous dimension of the quadratic chiral super field operator product for this purpose. The specific chiral superfield contents that we consider are $N_f$ copies of (i) $F+\bar F$, (ii) $Adj$, (iii) $S_2+\bar S_2$, and (iv) $A_2 + \bar A_2$, where $F$, $Adj$, $S_2$, and $A_2$ denote, respectively, the fundamental, adjoint, and symmetric and antisymmetric rank-2 tensor representations. We find that perturbative results slightly overestimate the value of $N_{f,cr}$ relative to the respective exact results for these representations, i.e., slightly underestimate the interval in $N_f$ for which the theory has infrared conformal behavior. Our results provide a measure of how closely perturbative calculations reproduce exact results for these theories.Comment: 16 pages, 3 figure

Ectoplasm & Superspace Integration Measure for 2D Supergravity with Four Spinorial Supercurrents

Building on a previous derivation of the local chiral projector for a two dimensional superspace with eight real supercharges, we provide the complete density projection formula required for locally supersymmetrical theories in this context. The derivation of this result is shown to be very efficient using techniques based on the Ectoplasmic construction of local measures in superspace.Comment: 18 pages, LaTeX; V2: minor changes, typos corrected, references added; V3: version to appear in J. Phys. A: Math. Theor., some comments and references added to address a referee reques

Current and future graphics requirements for LaRC and proposed future graphics system

The findings of an investigation to assess the current and future graphics requirements of the LaRC researchers with respect to both hardware and software are presented. A graphics system designed to meet these requirements is proposed

Complete Lagrangian formulation for N=4 topological string

We give a Lagrangian and display all local symmetries for N=4 topological string by Berkovits, Vafa and Siegel, the latter previously known in the superconformal gauge. Leading to a small N=4 superconformal algebra and exhibiting the manifest Lorentz invariance the model is proposed to be a framework for restoring the manifest Lorentz invariance in N=2 string scattering amplitudes.Comment: 8 pages, LaTex. One reference corrected, to appear in Phys. Rev.

Infusing interactive whiteboard technology into initial teacher education

This project examined the impact of collaboration between associate teachers and teacher candidates on the infusion of technology into the elementary classroom. Specifically, the research focused on the use of interactive whiteboard technology. Six teacher candidate-associate teacher pairs were brought together for training on the use of interactive whiteboards. Together they worked to design and implement classroom lessons using this technology. Data were collected from interviews with teacher candidates and associate teachers. Participants commented on the positive effects that collaboration had on the successful integration of technology in their junior-intermediate classrooms and the high level of student engagement. This project illustrates the importance of professional learning, community, and collaboration in successful technology infusion efforts

A haloarchaeal ferredoxin electron donor that plays an essential role in nitrate assimilation

In the absence of ammonium, many organisms, including the halophilic archaeon Haloferax volcanii DS2 (DM3757), may assimilate inorganic nitrogen from nitrate or nitrite, using a ferredoxin-dependent assimilatory NO3-/NO2- reductase pathway. The small acidic ferredoxin Hv-Fd plays an essential role in the electron transfer cascade required for assimilatory nitrate and nitrite reduction by the cytoplasmic NarB- and NirA-type reductases respectively. UV–visible absorbance and EPR spectroscopic characterization of purified Hv-Fd demonstrate that this protein binds a single [2Fe–2S] cluster, and potentiometric titration reveals that the cluster shares similar redox properties with those present in plant-type ferredoxins

The three-dimensional non-anticommutative superspace

We propose two alternative formulations for a three-dimensional non-anticommutative superspace in which some of the fermionic coordinates obey Clifford anticommutation relations. For this superspace, we construct the supersymmetry generators satisfying standard anticommutation relations and the corresponding supercovariant derivatives. We formulate a scalar superfield theory in such a superspace and calculate its propagator. We also suggest a prescription for the introduction of interactions in such theories.Comment: 9 pages, revtex4, v3: some clarifications and references added, version accepted for publication in Phys.Rev.

Extending Native Winter Pasture Use with Spring Grazing Practices

Improving profitability will help sustain the economic viability of ranch operations. Feed costs typically represent well over half of annual cow-calf production costs. Two things, 1) grazing strategies aimed at increasing the proportion of feed supplied through grazing and 2) decreasing reliance on high-cost harvested forages, have the potential to improve profit

After Wildfire: Range Recovery

In the grip of drought, livestock producers often must deal with the additional impact of wildfire. While drought conditions develop gradually and can be anticipated, losses due to wildfire are sudden and devastating

The quantum algebra of superspace

We present the complete set of $N=1$, $D=4$ quantum algebras associated to massive superparticles. We obtain the explicit solution of these algebras realized in terms of unconstrained operators acting on the Hilbert space of superfields. These solutions are expressed using the chiral, anti-chiral and tensorial projectors which define the three irreducible representations of the supersymmetry on the superfields. In each case the space-time variables are non-commuting and their commutators are proportional to the internal angular momentum of the representation. The quantum algebra associated to the chiral or the anti-chiral projector is the one obtained by the quantization of the Casalbuoni-Brink-Schwarz (superspin 0) massive superparticle. We present a new superparticle action for the (superspin 1/2) case and show that their wave functions are the ones associated to the irreducible tensor multiplet.Comment: 20 pages;changes in the nomenclatur