Cognitive performance in light current users and ex-users of ecstasy (MDMA) and controls

Previous research has shown that heavy users of ecstasy may suffer impaired cognitive functioning, and the present study set out to investigate whether such impairment might also be found in light users or ex-users of ecstasy. Sixty subjects, comprising 20 current light users, 20 ex-users, and 20 non-users of ecstasy, were tested on an extensive battery of cognitive tests. Current light users of ecstasy achieved significantly lower scores on the overall cognitive test battery than did the non-users (p=0.011), though there were no significant differences on any individual subtests. However, the scores obtained by the ex-users of ecstasy did not differ significantly from those of the non-users. It was concluded that current light users of ecstasy show a small but significant cognitive impairment, but that no such impairment is detectable in ex-users who had abstained from the drug for at least 6 months

The Shapes of AGB Envelopes as Probes of Binary Companions

We describe how the large scale geometry of the circumstellar envelopes of asymptotic giant branch stars can be used to probe the presence of unseen stellar companions. A nearby companion modifies the mass loss by gravitationally focusing the wind towards the orbital plane, and thereby determines the shape of the envelope at large distances from the star. Using available simulations, we develop a prescription for the observed shapes of envelopes in terms of the binary parameters, envelope orientation, and type of observation. The prescription provides a tool for the analysis of envelope images at optical, infrared, and millimetre wavelengths, which can be used to constrain the presence of companions in well observed cases. We illustrate this approach by examining the possible role of binary companions in triggering the onset of axi-symmetry in planetary nebula formation. If interaction with the primary leads to axi-symmetry, the spherical halos widely seen around newly formed nebulae set limits on the companion mass. Only low mass objects may orbit close to the primary without observable shaping effects: they remain invisible until the interaction causes a sudden change in the mass loss geometry.Comment: 11 pages, 7 figures, to appear in MNRA

Olive phenology as a sensitive indicator of future climatic warming in the Mediterranean

Experimental and modelling work suggests a strong dependence of olive flowering date on spring temperatures. Since airborne pollen concentrations reflect the flowering phenology of olive populations within a radius of 50 km, they may be a sensitive regional indicator of climatic warming. We assessed this potential sensitivity with phenology models fitted to flowering dates inferred from maximum airborne pollen data. Of four models tested, a thermal time model gave the best fit for Montpellier, France, and was the most effective at the regional scale, providing reasonable predictions for 10 sites in the western Mediterranean. This model was forced with replicated future temperature simulations for the western Mediterranean from a coupled ocean-atmosphere general circulation model (GCM). The GCM temperatures rose by 4·5 °C between 1990 and 2099 with a 1% per year increase in greenhouse gases, and modelled flowering date advanced at a rate of 6·2 d per °C. The results indicated that this long-term regional trend in phenology might be statistically significant as early as 2030, but with marked spatial variation in magnitude, with the calculated flowering date between the 1990s and 2030s advancing by 3–23 d. Future monitoring of airborne olive pollen may therefore provide an early biological indicator of climatic warming in the Mediterranean

The detached dust shells of AQ And, U Ant, and TT Cyg

Detached circumstellar dust shells are detected around three carbon variables using Herschel-PACS. Two of them are already known on the basis of their thermal CO emission and two are visible as extensions in IRAS imaging data. By model fits to the new data sets, physical sizes, expansion timescales, dust temperatures, and more are deduced. A comparison with existing molecular CO material shows a high degree of correlation for TT Cyg and U Ant but a few distinct differences with other observables are also found.Comment: Letter accepted for publication on the A&A Herschel Special Issu

Strongly magnetized pulsars: explosive events and evolution

Well before the radio discovery of pulsars offered the first observational confirmation for their existence (Hewish et al., 1968), it had been suggested that neutron stars might be endowed with very strong magnetic fields of $10^{10}$-$10^{14}$G (Hoyle et al., 1964; Pacini, 1967). It is because of their magnetic fields that these otherwise small ed inert, cooling dead stars emit radio pulses and shine in various part of the electromagnetic spectrum. But the presence of a strong magnetic field has more subtle and sometimes dramatic consequences: In the last decades of observations indeed, evidence mounted that it is likely the magnetic field that makes of an isolated neutron star what it is among the different observational manifestations in which they come. The contribution of the magnetic field to the energy budget of the neutron star can be comparable or even exceed the available kinetic energy. The most magnetised neutron stars in particular, the magnetars, exhibit an amazing assortment of explosive events, underlining the importance of their magnetic field in their lives. In this chapter we review the recent observational and theoretical achievements, which not only confirmed the importance of the magnetic field in the evolution of neutron stars, but also provide a promising unification scheme for the different observational manifestations in which they appear. We focus on the role of their magnetic field as an energy source behind their persistent emission, but also its critical role in explosive events.Comment: Review commissioned for publication in the White Book of "NewCompStar" European COST Action MP1304, 43 pages, 8 figure

The chemokine receptor CXCR2 and coronavirus-induced neurologic disease.

Inoculation with the neurotropic JHM strain of mouse hepatitis virus (MHV) into the central nervous system (CNS) of susceptible strains of mice results in an acute encephalomyelitis in which virus preferentially replicates within glial cells while excluding neurons. Control of viral replication during acute disease is mediated by infiltrating virus-specific T cells via cytokine secretion and cytolytic activity, however sterile immunity is not achieved and virus persists resulting in chronic neuroinflammation associated with demyelination. CXCR2 is a chemokine receptor that upon binding to specific ligands promotes host defense through recruitment of myeloid cells to the CNS as well as protecting oligodendroglia from cytokine-mediated death in response to MHV infection. These findings highlight growing evidence of the diverse and important role of CXCR2 in regulating neuroinflammatory diseases