The Profitability of Currency Speculation

This paper presents the results of a post-sample simulation of a speculative strategy using a portfolio of foreign currency forward contracts.The main new features of the speculative strategy are (a)the use of Kalman filters to update the forecasting equation, (b) the allowance for transactions,costs and margin requirements and (c) the endogenous determination of the leveraging of the portfolio. While the forecasting model tended to overestimate profit and underestimate risk, the strategy was still profitable over a three year period and it was possible to reject the hypothesis that the sum of profits was zero. Furthermore, the currency portfolio was found to have an extremely low market risk. Combinations of the speculative currency portfolio with traditional portfolios of U.S. equities resulted in considerable improvements in risk-adjusted returns on capital.

Highly-improved lattice field-strength tensor

We derive an O(a^4)-improved lattice version of the continuum field-strength tensor. Discretization errors are reduced via the combination of several clover terms of various sizes, complemented by tadpole improvement. The resulting improved field-strength tensor is used to construct O(a^4)-improved topological charge and action operators. We compare the values attained by these operators as we cool several configurations to self-duality with a previously defined highly-improved action and assess the relative scale of the remaining discretization errors.Comment: 22 pages, 7 postscript figure

Use of Residential Care in Europe for Children Aged Under Three: Some Lessons from Neurobiology

This critical commentary reviews the research into the use of residential care for children aged under three years and looks at some of the explanations that can be found for this in neurobiology. There continue to be high numbers and rates of these vulnerable children in institutions not only in the former Soviet states, but also in Western Europe. The new research provides strong evidence on the negative consequences for these children, particularly for those who remain in institutional care beyond the age of six months. Explanations from neurobiology sit well beside understandings drawn from attachment theory and start to show the mechanisms for this and also the ability of the brain to compensate

Human prostaglandin EP3 receptor isoforms show different agonist-induced internalization patterns

AbstractThe human prostaglandin EP3 receptor comprises eight isoforms that differ in carboxyl-tail. We show here that the isoforms are trafficked differently. When expressed in HEK293 cells, the isoforms located to the cell surface, although a fraction of some remained in the cell. Upon prostaglandin E2 stimulation, EP3.I internalized almost completely, EP3.II, EP3.V, EP3.VI and EP3.f internalized to a lesser extent and EP3.III and EP3.IV did not internalize. Both EP3.I and EP3.f internalized with β-arrestin and internalization were blocked by a dominant negative form of Eps15, a clathrin-associated protein. Although EP3.II internalized, β-arrestin did not translocate with the receptor and internalization was not blocked by mutant Eps15. EP3.V and EP3.VI internalized to discrete areas of the cell with β-arrestin

Establishing Social Work Practices in England: The Early Evidence

Social Work Practices (SWPs) were established in England in 2009 to deliver social work services to looked after children and care leavers. The introduction of independent social work-led organisations generated controversy focused on issues such as the privatisation of children's services and social workers' conditions of employment. This paper reports early findings from the evaluation of four of these pilots, drawing on interviews with children and young people, staff, and local authority and national stakeholders. The SWPs assumed a variety of organisational forms. The procurement process was demanding, with protracted negotiations over matters such as budgetary control and providing a round-the-clock service. Start-up was facilitated by an established relationship between the SWP provider and the local authority. Once operational, SWPs continued to rely on local authorities for various functions; in most cases, local authorities retained control of placement budgets. Levels of consultation and choice offered to children and young people regarding the move to an SWP varied considerably. Children's understanding about SWPs was generally low except in the pilot where most children retained their original social worker. These early findings show some dilution of the original SWP model, while the pilots' diversity allows the benefits of particular models to emerge

A Trajectory of Science Technology Engineering and Mathematics (STEM) Education in Papua New Guinea

For young students choosing the right career path is of fundamental importance. One has to be practical, logical and rational in deciding a career pathway. A correct choice may lead to prosperity while a wrong choice may lead to failure and lifelong frustration. Each individual has unique skills and talents, and they also have a unique set of triggers that help them acquire knowledge. Unfortunately, schools train, assess, and evaluate students in a very generic fashion, and therefore it is often difficult to pinpoint each individual’s interests and capabilities to give them a clear road map towards possible STEM career pathways. In this paper we will describe a solution to predict STEM career pathways concerning individual academic performance in the different subject areas studied by STEM students in Papua New Guinea (PNG)

Dynamic Adjustment and the Demand for International Reserves

Although there have been a large number of empirical studies of the demand for international reserves, there have not been many successful demonstrations that deviations of the actual stock of reserves from the target level defined by the demand function trigger a process of adjustment. This paper presents new evidence which suggests that central banks do have a target level of international reserve holdings, and that the adjustment of actual reserves towards the target level is quite rapid. In addition, an economic theory of the speed of adjustment is presented and tested. The evidence suggests that central banks adjust more rapidly to reserve deficiencies than to surpluses, that the speed of adjustment is positively related to the divergence between the actual level of reserves and the target level, and that countries which hold abnormally large quantities of reserves do so, in part, in order to adjust more slowly. Finally, the paper examines the applicability of the model to the current regime of managed flexible exchange rates. The evidence suggests that the move towards greater exchange rate flexibility has not significantly altered the reserve holding behavior of the world's central banks.

Quantitative comparison of filtering methods in lattice QCD

We systematically compare filtering methods used to extract topological excitations (like instantons, calorons, monopoles and vortices) from lattice gauge configurations, namely APE-smearing and spectral decompositions based on lattice Dirac and Laplace operators. Each of these techniques introduces ambiguities, which can invalidate the interpretation of the results. We show, however, that all these methods, when handled with care, reveal very similar topological structures. Hence, these common structures are free of ambiguities and faithfully represent infrared degrees of freedom in the QCD vacuum. As an application we discuss an interesting power-law for the clusters of filtered topological charge.Comment: 6 pages, 18 plots in 5 figures; final version as published in EPJ A; section 4 was adde

Using digital and hand printing techniques to compensate for loss: re-establishing colour and texture in historic textiles

Conservators use a range of 'gap filling' techniques to improve the structural stability and presentation of objects. Textile conservators often use fabric supports to provide reinforcement for weak areas of a textile and to provide a visual infill in missing areas. The most common technique is to use dyed fabrics of a single colour but while a plain dyed support provides good reinforcement, it can be visually obtrusive when used with patterned or textured textiles. Two recent postgraduate dissertation projects at the Textile Conservation Centre (TCC) have experimented with hand printing and digital imaging techniques to alter the appearance of support fabrics so that they are less visually obtrusive and blend well with the colour and texture of the textile being supported. Case studies demonstrate the successful use of these techniques on a painted hessian rocking horse and a knitted glove from an archaeological context

FLIC Fermions and Hadron Phenomenology

A pedagogical overview of the formulation of the Fat Link Irrelevant Clover (FLIC) fermion action and its associated phenomenology is described. The scaling analysis indicates FLIC fermions provide a new form of nonperturbative O(a) improvement where near-continuum results are obtained at finite lattice spacing. Spin-1/2 and spin-3/2, even and odd parity baryon resonances are investigated in quenched QCD, where the nature of the Roper resonance and Lambda(1405) are of particular interest. FLIC fermions allow efficient access to the light quark-mass regime, where evidence of chiral nonanalytic behavior in the Delta-baryon mass is observed.Comment: Invited plenary session talk at QNP 2002, International Conference on Quark-Nuclear Physics, 9-14 June 2002, Forschungszentrum Julich, German