SYMPOSIUM on forecasting the state of the public finances

The level of public borrowing plays a central role in UK government policymaking, especially in the run-up to each Budget. Accurate forecasts of the overall fiscal stance are crucial in assessing the general health of the economy, the direction of tax policy and the volume of public services that can be supplied. But these forecasts have a relatively poor record in the UK in recent years. The government’s last Financial Statement and Budget Report noted that ‘The budget deficit is the difference between two large aggregates of spending and receipts and forecasts of it are inevitably subject to a wide margin of error. Over the past five years the average absolute errors have been around 1 per cent of GDP, or plus or minus £8 billion in today’s prices’.

Variability of the Centimeter-Submillimeter Spectrum and Polarization of 3C 273 during Outburst

Original article can be found at: http://www.journals.uchicago.edu/ApJ/--Copyright University of Chicago Press/ AASCentimeter to submillimeter total flux and polarization monitoring data are used to investigate the nature of a prominent flare in the quasar 3C 273 during 1995/6. After removal of the quiescent level, the resulting “flare spectra" are well fitted by a simple homogeneous synchrotron source model, which in turn allows the movement of the self-absorption turnover to be tracked during the flare. Both the flare amplitude/time delay relationship and the overall spectral evolution are qualitatively consistent with existing models. The early evolution of the spectrum is best determined and is shown to be in excellent agreement with the Compton stage of the Marscher & Gear shock model. However, the polarization behavior during the flare is different at millimeter and centimeter wavelengths and the observations are difficult to reconcile with a simple transverse shock. They are, however, consistent with a conical shock for which the observed polarization properties vary with distance along the jet. Such variations may be caused, for example, by a change in cone angle owing to disruption caused by the growing component of the magnetic field parallel to the jet axis or by a moderate change in viewing angle.Peer reviewe

Incoherent pion photoproduction on the deuteron with polarization observables I: Formal expressions

Formal expressions are developed for the general five-fold differential cross section of incoherent $\pi$-photoproduction on the deuteron including beam and target polarization. The polarization observables of the cross section are described by various beam, target and beam-target asymmetries for polarized photons and/or polarized deuterons. They are given as bilinear hermitean forms in the reaction matrix elements divided by the unpolarized cross section. In addition, the corresponding observables for the semi-exclusive reaction $\vec d(\vec \gamma,\pi)NN$ are also given.Comment: 11 pages, 1 figur

Last scattering, relic gravitons and the circular polarization of the CMB

The tensor contribution to the $V$-mode polarization induced by a magnetized plasma at last scattering vanishes exactly. Conversely a polarized background of relic gravitons cannot generate a $V$-mode polarization. The reported results suggest that, in the magnetized $\Lambda$CDM paradigm, the dominant source of circular dichroism stems from the large-scale fluctuations of the spatial curvature.Comment: 8 pages, no figure

Heroin addiction: the past and future

Substance misuse, in particular heroin addiction contributes to health and social problems. Although effective medical treatment was available, earlier efforts confined the treatment of heroin addicts to in-house rehabilitation which required them to be estranged from the community and their families for 2 years. The in-house rehabilitative programme, implemented for at least three decades has produced low abstinence rates. On the other hand, being ‘away’ meant that many heroin addicts faced employment problems and family relationship difficulties upon completing the in-house rehabilitation. However, recently, the concerted efforts by various government and non-government organisations, and the acknowledgement that heroin addiction is a medical illness has resulted in a revamp to approaching treatment of heroin addiction. At present, methadone substitution programmes have been offered as part of treatment programme for heroin addicts in Malaysia. This new programme has been shown to be effective in treating heroin addiction and would need support and cooperation from all groups involved

Incoherent single pion electroproduction on the deuteron with polarization effects

Incoherent pion electroproduction on the deuteron is studied from threshold up to the second resonance region with special emphasis on the influence of final state interaction, in particular on polarization observables. The elementary $\gamma N\to\pi N$ amplitude is taken from the MAID-2003 model. Final state interaction is included by considering complete rescattering in the final $NN$ and $\pi N$ subsystems. Their influence on the structure functions governing the semi-exclusive differential cross section, where besides the scattered electron only the produced pion is detected, is investigated in detail. For charged pion-production the effect of $NN$-rescattering is moderate whereas $\pi N$-rescattering is almost negligible, except very close to threshold. $NN$-rescattering appears much stronger in neutral pion production for which the primary mechanism is the elimination of a significant spurious coherent contribution in the impulse approximation. Sizeable effects are also found in some of the polarization structure functions for beam and/or target polarizations.Comment: 20 pages including 14 figure

Expression of genes encoding the pre-TCR and CD3 complex during thymus development

The mature TCR is composed of a clonotypic heterodimer (αβor γδ) associated with the invariant CD3 components (γ, δ, ε and ζ). There is now considerable evidence that more immature forms of the TCR-CD3 complex (consisting of either CD3 alone or CD3 associated with a heterodimer of TCR β and pre-Tα) can be expressed at the cell surface on early thymocytes. These pre-TCR complexes are believed to be necessary for the ordered progression of early T cell development. We have analyzed in detail the expression of both the pre-TCR and CD3 complex at various stages of adult thymus development. Our data indicate that all CD3 components are already expressed at the mRNA level by the earliest identifiable (CD410) thymic precursor. In contrast, genes encoding the pre-TCR complex (pre-Tα and fully rearranged TCR β) are first expressed at the CD4410CD25+CD4−CD8− stage. Detectable surface expression of both CD3 and TCR β are delayed relative to expression of the corresponding genes, suggesting the existence of other (as yet unidentified) components of the pre-TCR comple