Testimony of Jack West Before the Commission on the Future of Worker-Management Relations

Testimony_ASQC_081094.pdf: 115 downloads, before Oct. 1, 2020

Expression, purification and initial characterization of Halobacterium proline dehydrogenase

Abstract only availableNature recycles proline by converting it to glutamate. This 4-electron oxidation process is catalyzed by two catabolic enzymes, proline dehydrogenase (PRODH) and Δ1-pyrroline-5-carboxylate dehydrogenase (P5CDH). Inborn defects in PRODH and P5CDH result in the disorders hyperprolinemia I & II, respectively. These conditions are often associated with mental retardation, convulsions, and brain disorders. PRODH has also been implicated in schizophrenia susceptibility, cancer and P53-mediated apoptosis. Despite their importance in human health and disease, these enzymes have not been extensively studied. Thus, the goal of this research is to characterize the structure and function of PRODH. The work presented here focuses on a newly discovered homologue of PRODH found in archaea, which we identified by bioinformatics analysis of genome sequence data. Archaea are also genetically more closely related to eukaryotes than bacteria, so study of their proteins may provide insights into homologous eukaryotic enzymes. Archaea are some of the Earth's oldest life forms and are known for living in extreme environments. The PRODH researched here is from the Halobacterium (salt-loving), which can be found in places such as the Dead Sea and the Great Salt Lake. Preliminary results so far include testing the expression of Halobacterium PRODH, known as YusM, in two different E. coli expression systems, BL21(DE3)pLysS and Rosetta2. The latter strain was used to account for rare codon usage by Halobacterium. Parameters varied in these expression tests included time and temperature of induction as well as IPTG concentration. After expression, the cells were broken in a French pressure cell and the cell debris was pelleted with centrifugation. YusM was found to be largely associated with the cell pellet; therefore protein purification under denaturing conditions was investigated. The use of urea as a denaturing reagent has been successful for purifying YusM. Once the protein was renatured it showed improved kinetic activity. We believe the improved activity is due to disruption of improperly folded protein by the denaturant, followed by re-folding into the native, or near-native, state. Further studies will need to be done to determine the cause of misfolding in the E. coli cell.Stevens' Chemistry Progra

The massless supersymmetric ladder with L rungs

We show that in the massless N=1 supersymmetric Wess-Zumino theory it is possible to devise a computational strategy by which the x-space calculation of the ladder 4-point correlators can be carried out without introducing any regularization. As an application we derive a representation valid at all loop orders in terms of conformal invariant integrals. We obtain an explicit expression of the 3-loop ladder diagram for collinear external points.Comment: LaTeX, 17 pages, 8 figure

Renormalization-Group Improved Effective Lagrangian for Interacting Theories in Curved Spacetime

A method for finding the renormalization group (RG) improved effective Lagrangian for a massive interacting field theory in curved spacetime is presented. As a particular example, the $\lambda \varphi^4$-theory is considered and the RG improved effective Lagrangian is explicitly found up to second order in the curvature tensors. As a further application, the curvature-induced phase transitions are discussed for both the massive and the massless versions of the theory. The problems which appear when calculating the RG improved effective Lagrangian for gauge theories are discussed, taking as example the asymptotically free SU(2) gauge model.Comment: 11 pages, LaTeX fil

Two-loop effective potential in quantum field theory in curved space-time

The method of the calculation of effective potential (in linear curvature approximation and at any loop) in massless gauge theory in curved space- time by the direct solution of RG equation is given.The closed expression for two-loop effective potential is obtained.Two-loop effective potential in scalar self-interacting theory is written explicitly.Some comments about it as well as about two-loop effective potential in standard model are presented.Comment: 8page

Contribution of matter fields to the Gell-Mann-Low function for N=1 supersymmetric Yang-Mills theory, regularized by higher covariant derivatives

Contribution of matter fields to the Gell-Mann-Low function for N=1 supersymmetric Yang-Mills theory, regularized by higher covariant derivatives, is obtained using Schwinger-Dyson equations and Slavnov-Tailor identities. A possible deviation of the result from the corresponding contribution in the exact Novikov, Shifman, Vainshtein and Zakharov $\beta$-function is discussed.Comment: 20 pages, 4 figure

N=1N=1 supersymmetry and the three loop anomalous dimension for the chiral superfield

We calculate the three loop anomalous dimension for a general $N=1$ supersymmetric gauge theory. The result is used to probe the possible existence of renormalisation invariant relationships between the Yukawa and gauge couplings.Comment: 18 pages. Uses Harvmac. Revised version includes discussion of the special case of the Wess-Zumino mode

Automatic Calculation of supersymmetric Renormalization Group Equations and Self Energies

SARAH is a Mathematica package for studying supersymmetric models. It calculates for a given model the masses, tadpole equations and all vertices at tree-level. Those information can be used by \SARAH to write model files for CalcHep/CompHep or FeynArts/FormCalc. In addition, the second version of SARAH can derive the renormalization group equations for the gauge couplings, parameters of the superpotential and soft-breaking parameters at one and two-loop level. Furthermore, it calculates the one-loop self energies and the one-loop corrections to the tadpoles. SARAH can handle all N=1 SUSY models whose gauge sector is a direct product of SU(N) and U(1) gauge groups. The particle content of the model can be an arbitrary number of chiral superfields transforming as any irreducible representation with respect to the gauge groups. To implement a new model, the user has just to define the gauge sector, the particle, the superpotential and the field rotations to mass eigenstates.Comment: 32 pages, some typoes corrected, matches published versio

Holomorphic Anomalies and the Nonrenormalization Theorem

It has been argued that the superpotential can be renormalized in the presence of massless particles. Possible implications which have been considered include the restoration of supersymmetry at higher loops or a shift to a supersymmetric vacuum state. We argue that even in the presence of massless particles, there are no new contributions to the superpotential at any order in perturbation theory. This confirms the utility of the Wilsonian superpotential for analyzing the moduli space of the low energy theory.Comment: 9 pages, LaTeX, 1 .ps figure, psfig.sty include

Non-renormalization theorems without supergraphs: The Wess-Zumino model

The non-renormalization theorems of chiral vertex functions are derived on the basis of an algebraic analysis. The property, that the interaction vertex is a second supersymmetry variation of a lower dimensional field monomial, is used to relate chiral Green functions to superficially convergent Green functions by extracting the two supersymmetry variations from an internal vertex and transforming them to derivatives acting on external legs. The analysis is valid in the massive as well as in the massless model and can be performed irrespective of properties of the superpotential at vanishing momentum.Comment: 20 pages, Latex, added acknowledgment