Smart mobile phones are a widely available class of computing platforms with rich internal devices and a communications infrastructure that can be appropriated and exploited to support environmental sensing, social networks, and healthcare applications. In this article, the authors discuss experiences and lessons learned from deploying four mobile sensing applications on off-the-shelf mobile phones in a framework called MobSens that contains elements of health, social, and environmental sensing at both individual and community levels. They describe the main components of these applications, which facilitate logging and external communications. They also outline the challenges faced when building and testing such applications and describe their strategies for overcoming them.

A compact ribbon cassette for dispensing and storing a ribbon or tape. The supply and take-up rolls of ribbon and tape are disposed upon a common rotatable shaft mounted for rotation within the housing. A unique chevron disposed adjacent the take-up roll and on the post-printing portion of the cassette causes the dispensed ribbon to reverse direction and change level and be presented for storage upon the take-up roll. Ink particles are removed by a wiper from the ribbon prior to printing.

He was also enthusiastic about all things British: Scottish whisky, the adventures of Harry Potter and, after I had introduced him to it, the music of Edward Elgar, are some examples. On one occasion his being an anglophile avoided what might have been an awkward international incident. As President of the French Physical Society he was entertained to a formal dinner by the Institute of Physics in Britain. Unfortunately, and I am sure completely unintentionally, the IoP had arranged for it to be held in a hotel and when they arrived there they discovered that the dinner was laid out in its Waterloo Room. Maurice told me about it with great amusement.

Learn about projects on participant-environment interaction, the leveraging of information from mobile sensors, user authentication, and urban computing navigation.

Regge theory provides an excellent description of small-$x$ structure-function data from $Q^2=0$ up to the highest available values. The large-$Q^2$ data should also be described by perturbative QCD: the two descriptions must agree in the region where they overlap. However, at present there is a serious lack in our understanding of how to apply perturbative QCD at small $x$. The usual lowest-order or next-to-lowest order expansion is not valid, at least not until $Q^2$ becomes much larger than is usually assumed; a resummation is necessary, but as yet we do not know how to do this resummation.

Regge theory provides an excellent description of small-x structurefunction data from Q = 0 up to the highest available values. The large-Q data should also be described by perturbative QCD: the two descriptions must agree in the region where they overlap. However, at present there is a serious lack in our understanding of how to apply perturbative QCD at small x. The usual lowestorder or next-to-lowest order expansion is not valid, at least not until Q becomes much larger than is usually assumed; a resummation is necessary, but as yet we do not know how to do this resummation.

A review is given of recent attempts to establish a useful prescription for perturbation-theory calculations in the temporal gauge Ao = 0, at both zero and nonzero temperature. These attempts are not yet completely successful.

Gauge Theories in Particle Physics: A Practical Introduction. By Ian J.R. Aitchison and Anthony J.G. Hey. Pp.341. Pbk ISBN 0-85274-534-6. (Adam Hilger/Heyden: 1982.) £14.50, $36.