The application of photonics to astronomy offers major advantages in the area of highly-multiplexed spectroscopy, especially when applied to extremely large telescopes. These include the suppression of the near-infrared night-sky spectrum [J. Bland-Hawthorn et al, Opt. Express 12, 5902 (2004), S. G. Leon-Saval et al, Opt. Lett. 30, 2545 (2005)] and the miniaturisation of spectrographs so that t...

We measure momentum transferred from a single pulse of a standing wave of light to a sample of ultracold sodium atoms, and observe a sharp increase in the momentum transfer when the pulse duration exceeds a critical value tcr . A classical analysis of nonlinear resonances shows that resonance overlap occurs at tcr , and there is a transition to global classical chaos. These results are a direct...

alphabeta and gammadelta T cell lineages develop in the thymus from a common precursor. It is unclear at which stage of development commitment to these lineages takes place and in which way T cell receptor signaling contributes to the process. Recently, it was demonstrated that strong TCR signals favor gammadelta lineage development, whereas weaker TCR signals promote alphabeta lineage fate. Tw...

The mechanism by which the ligand occupancy state of the T cell receptor complex is converted into intracellular signaling information has been a controversial topic. Although the majority of structural studies argue against a conformational change, recent studies support the possibility for such a change within the CD3 components of the TCR complex. In this commentary, the evidence for TCR con...

By SIR ALFRED YARROW, F.R.S. [Sir Alfred Yarrow's rearrangement of the beds in his Convalescent Home for Children at Broadstairs, as a means of reducing the risk of infection, has attracted a good deal of attention. In the following article Sir Alfred describes the innovation, and the reasons for it. | I T will be seen from the accompanying photograph that the heads of the children are placed a...

Breast cancer is the second main cause of death among women. The use of medicinal plants has been common in many countries since ancient times. The aim of this study was to evaluate the antioxidant and anti-proliferative potential of Achillea millefolium L. The antioxidant activity of the aqueous and hydroalcoholic extracts of Achillea millefolium L. leaf and flower was measured by DPPH and FRA...