Three-loop HTL QCD thermodynamics

The hard-thermal-loop perturbation theory (HTLpt) framework is used to calculate the thermodynamic functions of a quark-gluon plasma to three-loop order. This is the highest order accessible by finite temperature perturbation theory applied to a non-Abelian gauge theory before the high-temperature infrared catastrophe. All ultraviolet divergences are eliminated by renormalization of the vacuum, the HTL mass parameters, and the strong coupling constant. After choosing a prescription for the mass parameters, the three-loop results for the pressure and trace anomaly are found to be in very good agreement with recent lattice data down to $T \sim 2-3\,T_c$, which are temperatures accessible by current and forthcoming heavy-ion collision experiments.Comment: 27 pages, 11 figures; corresponds with published version in JHE

Convergence and Gauge Dependence Properties of the Resummed One-loop Quark-Quark Scattering Amplitude in Perturbative QCD

The one-loop QCD effective charge $\alpha_s^{eff}$ for quark-quark scattering is derived by diagrammatic resummation of the one-loop amplitude using an arbitary covariant gauge. Except for the particular choice of gauge parameter $\xi = -3$, $\alpha_s^{eff}$ is found to {\it increase} with increasing physical scale, $Q$, as $\ln Q$ or $\ln^2 Q$. For $\xi = -3$, $\alpha_s^{eff}$ decreases with increasing $Q$ and satisfies a renormalisation group equation. Also, except for the case $\xi = 19/9$, convergence radii of geometric series are found to impose upper limits on $Q$.Comment: 28 pages, 5 tables, 5 figures. v3 The one-loop amplitudes in Section 2 are recalculated using dimensional regularisation, and several errors in the on-shell calculation of Reference[1] are pointed out. v4 one figure removed one added. Three tables and new text in Section 5 added. Published versio

Investigation of the Domain Wall Fermion Approach to Chiral Gauge Theories on the Lattice

We investigate a recent proposal to construct chiral gauge theories on the lattice using domain wall fermions. We restrict ourselves to the finite volume case, in which two domain walls are present, with modes of opposite chirality on each of them. We couple the chiral fermions on only one of the domain walls to a gauge field. In order to preserve gauge invariance, we have to add a scalar field, which gives rise to additional light mirror fermion and scalar modes. We argue that in an anomaly free model these extra modes would decouple if our model possesses a so-called strong coupling symmetric phase. However, our numerical results indicate that such a phase most probably does not exist. ---- Note: 9 Postscript figures are appended as uuencoded compressed tar file.Comment: 27p. Latex; UCSD/PTH 93-28, Wash. U. HEP/93-6

An Economic Explanation of the Early Bank of Amsterdam, Debasement, Bills of Exchange, and the Emergence of the First Central Bank

The Bank of Amsterdam, founded in 1609, was the first public bank to offer accounts not directly convertible to coin. As such, it can be described as the first true central bank. The debut of central bank money did not result from any conscious policy decision, however, but instead arose almost by accident, in response to the chaotic monetary conditions during the early years of the Dutch Republic. This paper examines the history of this momentous development from the perspective of modern monetary theory

Cost-effectiveness of conservative treatments for neck pain: a systematic review on economic evaluations

PURPOSE: Various conservative interventions have been used for the treatment of non-specific neck pain. The aim of this systematic review was to investigate the cost-effectiveness of conservative treatments for non-specific neck pain. METHODS: Clinical and economic electronic databases, reference lists and authors’ databases were searched up to 13 January 2011. Two reviewers independently selected studies for inclusion, performed the risk of bias assessment and data extraction. RESULTS: A total of five economic evaluations met the inclusion criteria. All studies were conducted alongside randomised controlled trials and included a cost-utility analysis, and four studies also conducted a cost-effectiveness analysis. Most often, the economic evaluation was conducted from a societal or a health-care perspective. One study found that manual therapy was dominant over physiotherapy and general practitioner care, whilst behavioural graded activity was not cost-effective compared to manual therapy. The combination of advice and exercise with manual therapy was not cost-effective compared to advice and exercise only. One study found that acupuncture was cost-effective compared to a delayed acupuncture intervention, and another study found no differences on cost-effectiveness between a brief physiotherapy intervention compared to usual physiotherapy. Pooling of the data was not possible as heterogeneity existed between the studies on participants, interventions, controls, outcomes, follow-up duration and context related socio-political differences. CONCLUSION: At present, the limited number of studies and the heterogeneity between studies warrant no definite conclusions on the cost-effectiveness of conservative treatments for non-specific neck pain

The Big Problem of Large Bills: The Bank of Amsterdam and the Origins of Central Banking

This paper outlines a model of the first true central bank, the Bank of Amsterdam, founded in 1609. Employing a variant of the Freeman (1996) model of money and payments, we first analyze the problematic monetary situation in the Netherlands prior to the founding of the Bank. We then use the model to describe how the Bank could remedy this situation by creating a stable medium for the settlement of commercial obligations

Effectiveness of behavioural graded activity compared with physiotherapy treatment in chronic neck pain: design of a randomised clinical trial [ISRCTN88733332]

BACKGROUND: Chronic neck pain is a common complaint in the Netherlands with a point prevalence of 14.3%. Patients with chronic neck pain are often referred to a physiotherapist and, although many treatments are available, it remains unclear which type of treatment is to be preferred. The objective of this article is to present the design of a randomised clinical trial, Ephysion, which examines the clinical and cost effectiveness of behavioural graded activity compared with a physiotherapy treatment for patients with chronic non-specific neck pain. METHODS: Eligible patients with non-specific neck pain persisting longer than 3 months will be randomly allocated to either the behavioural graded activity programme or to the physiotherapy treatment. The graded activity programme is based on an operant approach, which uses a time-contingent method to increase the patient's activity level. This treatment is compared with physiotherapy treatment using a pain-contingent method. Primary treatment outcome is the patient's global perceived effect concerning recovery from the complaint. Global perceived effect on daily functioning is also explored as primary outcome to establish the impact of treatment on daily activity. Direct and indirect costs will also be assessed. Secondary outcomes include the patient's main complaints, pain intensity, medical consumption, functional status, quality of life, and psychological variables. Recruitment of patients will take place up to the end of the year 2004 and follow-up measurement will continue until end 2005