On the attempts to measure water (and other volatiles) directly at the surface of a comet.

The Ptolemy instrument on the Philae lander (of the Rosetta space mission) was able to make measurements of the major volatiles, water, carbon monoxide and carbon dioxide, directly at the surface of comet 67P/Churyumov-Gerasimenko. We give some background to the mission and highlight those instruments that have already given insights into the notion of water in comets, and which will continue to do so as more results are either acquired or more fully interpreted. On the basis of our results, we show how comets may in fact be heterogeneous over their surface, and how surface measurements can be used in a quest to comprehend the daily cycles of processes that affect the evolution of comets.

COMETARY SCIENCE. CHO-bearing organic compounds at the surface of 67P/Churyumov-Gerasimenko revealed by Ptolemy.

The surface and subsurface of comets preserve material from the formation of the solar system. The properties of cometary material thus provide insight into the physical and chemical conditions during their formation. We present mass spectra taken by the Ptolemy instrument 20 minutes after the initial touchdown of the Philae lander on the surface of comet 67P/Churyumov-Gerasimenko.

Ion trap mass spectrometry on a comet nucleus: the Ptolemy instrument and the Rosetta space mission.

In May 2014, the Rosetta spacecraft is scheduled to rendezvous with the comet Churyumov-Gerasimenko ('67P'). One of the instruments on board the 'Lander' which will descend on to the surface of the comet is a miniaturised GC/MS system that incorporates an ion trap mass spectrometer, specially developed for isotope ratio analysis. This article describes the development and optimisation of the ion trap for this unique application, and presents a summary of the range of pre-programmed experiments that will contribute to the characterisation of the solid and volatile cometary materials.

The use of static mass spectrometry to determine the combined stable isotopic composition of small samples of atmospheric methane.

Global budgets of atmospheric trace gases are increasingly being constrained by means of stable isotope measurements. Published analytical techniques for studying the parallel stable isotopic composition of methane (delta(13)C and deltaD) require prohibitively large quantities of methane for analysis, making them unsuitable for studies where sample size is small, e.g.

Diurnal variation of intensive running in food-deprived rats.

Manipulation of the food supply can induce either intense hyperactive wheel running or a fatal activity anorexia in rats that is strongly analogous to that seen in humans. The abnormal behaviour is accompanied by alterations in the diurnal pattern of activity. As part of a detailed study of hyperactivity and anorexia, spontaneous wheel running by male rats was studied under three conditions: ad libitum feeding; restriction to 15 g of food per day; and restriction to a single 90-min meal per day.

Diffusion and Electric Mobility of KCI within Isolated Cuticles of Citrus aurantium.

Fick's second law has been used to predict the time course of electrical conductance change in isolated cuticles following the rapid change in bathing solution (KCI) from concentration C to 0.1 C. The theoretical time course is dependent on the coefficient of diffusion of KCI in the cuticle and the cuticle thickness.