Two cases of submucosal haematoma of the oesophagus and Mallory-Weiss tear.

Submucosal haematoma of the oesophagus is an uncommon condition which may be under-recognised. Presentation may be with chest pain, dysphagia or haematemesis. Endoscopy, CT scan, barium meal or a combination of these modalities makes the diagnosis. Most patients make a full recovery.

The effects of temperature and moisture on CO2 uptake and total resistance to water loss in the antarctic foliose lichen Umbilicaria antarctica.

Maximum net photosynthesis of field-fresh thalli, illuminated at 200 µmol photons m-2 s-1 (PAR), was attained at 13 °C and 1.10 g g-1 water content. Small but significant rates of photosynthesis were measured at -5.5 °C. Depression of net photosynthesis at high thallus water contents is explained in terms of thallus anatomy. Calculation of evaporative resistance of the thallus by a new method showed a moisture-dependent response pattern, and was in agreement with direct observations made on other foliose species.