One-particle reducible contribution to the one-loop scalar propagator in a constant field

Recently, Gies and Karbstein showed that the two-loop Euler-Heisenberg Lagrangian receives a finite one-particle reducible contribution in addition to the well-known one-particle irreducible one. Here, we demonstrate that a similar contribution exists for the propagator in a constant field already at the one-loop level, and we calculate this contribution for the scalar QED case. We also present an independent derivation of the Gies-Karbstein result using the worldline formalism, treating the scalar and spinor QED cases in a unified manner.Comment: 13 pages, 4 figures. Minor corrections mad

Mixed symmetry tensors in the worldline formalism

We consider the first quantised approach to quantum field theory coupled to a non-Abelian gauge field. Representing the colour degrees of freedom with a single family of auxiliary variables the matter field transforms in a reducible representation of the gauge group which - by adding a suitable Chern-Simons term to the particle action - can be projected onto a chosen fully (anti-)symmetric representation. By considering F families of auxiliary variables, we describe how to extend the model to arbitrary tensor products of F reducible representations, which realises a U(F) "flavour" symmetry on the worldline particle model. Gauging this symmetry allows the introduction of constraints on the Hilbert space of the colour fields which can be used to project onto an arbitrary irreducible representation, specified by a certain Young Tableau. In particular the occupation numbers of the wavefunction - i.e. the lengths of the columns (rows) of the Young Tableau - are fixed through the introduction of Chern-Simons terms. We verify this projection by calculating the number of colour degrees of freedom associated to the matter field. We suggest that, using the worldline approach to quantum field theory, this mechanism will allow the calculation of one-loop scattering amplitudes with the virtual particle in an arbitrary representation of the gauge group.Comment: 1+32 page

An annotated bibliography of tax compliance and tax compliance costs

An annotated bibliography of tax compliance and tax compliance costs.tax; tax compliance; compliance costs; bibliography; tax evasion; tax avoidance; auditing; tax simplification

Emergency Management Training for Transportation Agencies

State transportation agencies have a variety of responsibilities related to emergency management. Field personnel manage events--from day-to-day emergencies to disasters--using the Incident Command System (ICS) as their organizational basis. At the headquarters level, the Emergency Operations Center (EOC) coordinates the use of resources across the department and its districts, with other state departments and agencies, and through the federal Emergency Support Function 1. District-level EOCs coordinate with the department. In extreme events, the transportation department may only be able to deliver limited essential services in austere conditions, so a continuity of operations/ continuity of government plan (COOP/COG) is essential. This research applied the principles of andragogy to deliver ICS field level training, EOC training and COOP/COG training to state transportation agency’s staff in all districts and at headquarters. The data supports the need for adult-oriented methods in emergency management training

Taking ownership: The story of a successful partnership for change in a Pacific Island science teacher education setting.

This paper explores an example of a partnership approach that appears to be producing sustainable change in a Pacific Islands education setting. The people involved report on the way science education staff from the Solomon Islands School of Education (SOE) and staff from the Faculty of Education University of Waikato (UOW), New Zealand worked together on the redevelopment of undergraduate science education courses for the SOE. Together we sought to identify significant factors supporting the process. The development required significant change and posed a number of challenges yet resulted in local staff producing high quality materials and programmes and taking ownership of ongoing development. More importantly, there was significant personal professional learning in both science education and initial teacher education for local Solomon Islands staff. Factors contributing to the success of the partnership are explored through the perceptions of the participants and include the quality of relationship, mutual respect, emphasis on conceptual agreement when working together, and the involvement of local staff in decision-making

Transcriptional downregulation of agr expression in Staphylococcus aureus during growth in human serum can be overcome by constitutively active mutant forms of the sensor kinase AgrC

The temporal and cell density-dependent regulation of expression of virtually all the Staphylococcus aureus virulon is under the control of the agr (accessory gene regulatory) operon. The expression of the agr operon is subject to transcriptional regulation by the AgrA/C two-component response regulator/sensor kinase pair. During bacteraemia, a frequent syndrome caused by methicillin-resistant S. aureus (MRSA), the transcriptional downregulation of agr expression has been attributed to the sequestration of the quorum-signalling molecule auto-inducing peptide (AIP) by the human serum component apolipoprotein B as part of an innate immune response to infection. However, it is not known whether transcriptional downregulation of agr expression during growth in human serum is additionally subjected to regulation by transcription regulatory proteins that either directly or indirectly affect transcription from the agr operon promoters. Here, using chromosomal fluorescence reporters of agr expression in S. aureus, we show that the transcriptional downregulation of agr expression in human serum can be overcome using constitutive active mutant forms of AgrC. Therefore, it seems that the sequestration of the AIP is likely to be the only mechanism by which the host innate immune response limits agr expression at the transcriptional level to maintain the host–pathogen balance towards a noninvasive outcome

Characterization of mutations and loss of heterozygosity of p53 and K-\u3ci\u3eras\u3c/i\u3e2 in pancreatic cancer cell lines by immobilized polymerase chain reaction

Background The identification of known mutations in a cell population is important for clinical applications and basic cancer research. In this work an immobilized form of the polymerase chain reaction, referred to as polony technology, was used to detect mutations as well as gene deletions, resulting in loss of heterozygosity (LOH), in cancer cell lines. Specifically, the mutational hotspots in p53, namely codons 175, 245, 248, 249, 273, and 282, and K-ras2, codons 12, 13 and 61, were genotyped in the pancreatic cell line, Panc-1. In addition LOH analysis was also performed for these same two genes in Panc-1 by quantifying the relative gene copy number of p53 and K-ras2. Results Using polony technology, Panc-1 was determined to possess only one copy of p53, which possessed a mutation in codon 273, and two copies of K-ras2, one wildtype and one with a mutation in codon 12. To further demonstrate the general approach of this method, polonies were also used to detect K-ras2 mutations in the pancreatic cell lines, AsPc-1 and CAPAN-1. Conclusions In conclusion, we have developed an assay that can detect mutations in hotspots of p53 and K-ras2 as well as diagnose LOH in these same genes

Do Individual Accounts Postpone Retirement: Evidence from Chile

Postponing retirement will become increasingly important as a means to increase the labor force, its output and old age security, as populations age. Recent research has focused on incentives stemming from the social security system that influence the worker’s decision to retire. Defined benefit systems (both public and private) often contain penalties for postponing access to pensions or continuing to work while receiving a pension. In contrast, the tight link between contributions and accumulations and the actuarial conversion of accumulations into pensions in privately managed defined contribution systems may lead workers to postpone pensions or to continue working after withdrawals begin. The experience of Chile, which implemented its new system in 1982, offers an opportunity to test if the change in incentives has indeed produced the expected change in retirement behavior. Using probit analysis of household survey data from 1960 to 2002, we estimate the impact of the pension reform on the probability of 1) becoming a pensioner and 2) dropping out of the labor force, for older workers. We find strong effects of the new system on both propensities, in the aggregate and at the individual level after controlling for individual and macro-economic variables. In particular, restricted access to early pensions and the exemption of pensioners from the pension payroll tax appear to exert a powerful effect on labor force participation rates.

Social Security Rules and Labor Force Participation of Older Workers: Evidence from Chile

Recent research has argued that incentives stemming from social security systems influence the worker’s decision to retire. The experience of Chile, which radically changed its system in 1981, offers an opportunity to test this hypothesis. The new system tightened access to early pensions, replaced an actuarially unfair defined benefit plan with an actuarially fair defined contribution plan, exempted pensioners from the pension payroll tax and allowed widows to keep their own pension in addition to their survivor’s benefit. Although the old system is being phased out, since 1981 the two systems have co-existed. Using probit analysis of the behavior of a retrospective sample of new and old system affiliates, we estimate the impact of the new social security rules on the probability of dropping out of the labor force, for older workers. We find large effects. Age of pensioning has been postponed. Labor force participation is much higher among affiliates of the new system compared with the old, especially for pensioners and women. This is not simply due to selection: Aggregate participation rates have increased as the new system’s share of total affiliates has risen.