On the Viability of Lattice Perturbation Theory

In this paper we show that the apparent failure of QCD lattice perturbation theory to account for Monte Carlo measurements of perturbative quantities results from choosing the bare lattice coupling constant as the expansion parameter. Using instead ``renormalized'' coupling constants defined in terms of physical quantities, like the heavy-quark potential, greatly enhances the predictive power of lattice perturbation theory. The quality of these predictions is further enhanced by a method for automatically determining the coupling-constant scale most appropriate to a particular quantity. We present a mean-field analysis that explains the large renormalizations relating lattice quantities, like the coupling constant, to their continuum analogues. This suggests a new prescription for designing lattice operators that are more continuum-like than conventional operators. Finally, we provide evidence that the scaling of physical quantities is asymptotic or perturbative already at $\beta$'s as low as 5.7, provided the evolution from scale to scale is analyzed using renormalized perturbation theory. This result indicates that reliable simulations of (quenched) QCD are possible at these same low $\beta$'s.Comment: 3

Non-classical computing: feasible versus infeasible

Physics sets certain limits on what is and is not computable. These limits are very far from having been reached by current technologies. Whilst proposals for hypercomputation are almost certainly infeasible, there are a number of non classical approaches that do hold considerable promise. There are a range of possible architectures that could be implemented on silicon that are distinctly different from the von Neumann model. Beyond this, quantum simulators, which are the quantum equivalent of analogue computers, may be constructable in the near future

A computational method for the coupled solution of reaction–diffusion equations on evolving domains and manifolds: application to a model of cell migration and chemotaxis

In this paper, we devise a moving mesh finite element method for the approximate solution of coupled bulk–surface reaction–diffusion equations on an evolving two dimensional domain. Fundamental to the success of the method is the robust generation of bulk and surface meshes. For this purpose, we use a novel moving mesh partial differential equation (MMPDE) approach. The developed method is applied to model problems with known analytical solutions; these experiments indicate second-order spatial and temporal accuracy. Coupled bulk–surface problems occur frequently in many areas; in particular, in the modelling of eukaryotic cell migration and chemotaxis. We apply the method to a model of the two-way interaction of a migrating cell in a chemotactic field, where the bulk region corresponds to the extracellular region and the surface to the cell membrane

Follow the leader or the pack? Regulatory focus and academic entrepreneurial intentions

Drawing on the academic entrepreneurship and regulatory focus theory literature, and applying a multilevel per- spective, this paper examines why university academics intend to engage in formal (spin-off or start-up companies and licensing university research) or informal (collaborative research, contract research, continuous professional development, and contract consulting) commercialization activities and the role local contextual factors, in partic- ular leaders and work-group colleagues (peers), play in their commercialization choices. Based on a survey of 395 science, technology, engineering, and mathematics (STEM) academics working in 14 Scottish universities, the research findings suggest that an individual’s chronic regulatory focus has a direct effect on their formal and informal commercialization intent. The results reveal that the stronger an individual’s chronic promotion focus the stronger their formal and informal commercialization intentions and a stronger individual chronic prevention focus leads to weaker intentions to engage in informal commercialization. In addition, when contextual interaction effects are considered, leaders and workplace colleagues have different influences on commercialization intent. On the one hand, promotion-focused leaders can strengthen and prevention-focused leaders can under certain cir- cumstances weaken a promotion-focused academic’s formal commercialization intent. On the other hand, the level of workplace colleague engagement, acting as a reference point, strengthens not only promotion-focused academ- ics’ intent to engage in formal commercialization activities, but also prevention-focused academics’ corresponding informal commercialization intent. As such, universities should consider the appointment of leaders who are strong role models and have a track record in formal and/or informal commercialization activities and also con- sider the importance workplace colleagues have on moderating an academic’s intention to engage in different forms of commercialization activities

Expected Precision of Higgs Boson Partial Widths within the Standard Model

We discuss the sources of uncertainty in calculations of the partial widths of the Higgs boson within the Standard Model. The uncertainties come from two sources: the truncation of perturbation theory and the uncertainties in input parameters. We review the current status of perturbative calculations and note that these are already reaching the parts-per-mil level of accuracy for the major decay modes. The main sources of uncertainty will then come from the parametric dependences on alpha_s, m_b, and m_c. Knowledge of these parameters is systematically improvable through lattice gauge theory calculations. We estimate the precision that lattice QCD will achieve in the next decade and the corresponding precision of the Standard Model predictions for Higgs boson partial widths.Comment: 20 pages, 1 figure; v2: minor typo correction

Nonperturbative ``Lattice Perturbation Theory''

We discuss a program for replacing standard perturbative methods with Monte Carlo simulations in short distance lattice gauge theory calculations.Comment: 3 pages, uuencoded Latex file, two embedded figures and .sty file include

Targeting Glycolysis with Epigallocatechin-3-Gallate Enhances the Efficacy of Chemotherapeutics in Pancreatic Cancer Cells and Xenografts.

Pancreatic cancer is a complex disease, in need of new therapeutic approaches. In this study, we explored the effect and mechanism of action of epigallocatechin-3-gallate (EGCG), a major polyphenol in green tea, alone and in combination with current chemotherapeutics on pancreatic cancer cell growth, focusing on glycolysis metabolism. Moreover, we investigated whether EGCG's effect is dependent on its ability to induce reactive oxygen species (ROS). EGCG reduced pancreatic cancer cell growth in a concentration-dependent manner and the growth inhibition effect was further enhanced under glucose deprivation conditions. Mechanistically, EGCG induced ROS levels concentration-dependently. EGCG affected glycolysis by suppressing the extracellular acidification rate through the reduction of the activity and levels of the glycolytic enzymes phosphofructokinase and pyruvate kinase. Cotreatment with catalase abrogated EGCG's effect on phosphofructokinase and pyruvate kinase. Furthermore, EGCG sensitized gemcitabine to inhibit pancreatic cancer cell growth in vitro and in vivo. EGCG and gemcitabine, given alone, reduced pancreatic tumor xenograft growth by 40% and 52%, respectively, whereas the EGCG/gemcitabine combination reduced tumor growth by 67%. EGCG enhanced gemcitabine's effect on apoptosis, cell proliferation, cell cycle and further suppressed phosphofructokinase and pyruvate kinase levels. In conclusion, EGCG is a strong combination partner of gemcitabine reducing pancreatic cancer cell growth by suppressing glycolysis

Magnetic field induced rotation of the d-vector in Sr_2RuO_4

The superconductor Sr_2RuO_4 is widely believed to be a spin triplet system with a chiral order parameter analogous to the A phase of superfluid helium-3. The best evidence for this pairing state is that the Knight shift or spin susceptibility measured in neutron scattering is constant below T_c, unlike in a spin-singlet superconductor. The original Knight shift and neutron scattering measurements were performed for magnetic fields aligned in the ruthenate a-b plane. These would be consistent with a triplet d-vector d{k} aligned along the c-axis. However recently the Knight shift for fields along c was also found to be constant below T_c, which is not expected for this symmetry state. In this paper we show that while spin-orbit interaction stabilises the c-axis oriented d-vector, it is possible that only a very small external B field may be sufficient to rotate the d-vector into the a-b plane. In this case the triplet pairing model remains valid. We discuss characteristics of the transition and the prospects to detect it in thermodynamic quantities.Comment: 2 pages, 1 figure, Proceedings of the M2S-HTSC conference in Dresden. Requires elsart.sty (included

Creating market failure: business-government relations in the British paper-pulp industry, 1950–1980

This article examines the nuances and complexities of business-government relations in the British paper-pulp industry between 1950 and 1980 through the prism of interactions between Wiggins, Teape & Co., a paper company, and various U.K. government departments in the postwar period. It highlights the complexity of business-government and interdepartmental relations and tensions, set against the global and domestic paper industry competition and the United Kingdom’s international economic position. Longstanding industry underinvestment and interdepartmental tensions in government are identified as principal contributors to the failing competitiveness of the industry and of British businesses more generally in the twentieth century