Episodic memory deficits are a core feature of neurodegenerative disorders. Muscarinic M1 receptors play a critical role in modulating learning and memory and are highly expressed in the hippocampus. We examined the effect of GSK1034702, a potent M1 receptor allosteric agonist, on cognitive function, and in particular episodic memory, in healthy smokers using the nicotine abstinence model of cognitive dysfunction. The study utilized a randomized, double-blind, placebo-controlled, cross-over design in which 20 male nicotine abstained smokers were tested following single doses of placebo, 4 and 8 mg GSK1034702. Compared to the baseline (nicotine on-state), nicotine abstinence showed statistical significance in reducing immediate (p=0.019) and delayed (p=0.02) recall. GSK1034702 (8 mg) significantly attenuated (i.e. improved) immediate recall (p=0.014) but not delayed recall. None of the other cognitive domains was modulated by either nicotine abstinence or GSK1034702. These findings suggest that stimulating M1 receptor mediated neurotransmission in humans with GSK1034702 improves memory encoding potentially by modulating hippocampal function. Hence, selective M1 receptor allosteric agonists may have therapeutic benefits in disorders of impaired learning including Alzheimer's disease.

We consider families of quasiplatonic Riemann surfaces characterised by the fact that – as in the case of Fermat curves of exponent n – their underlying regular (Walsh) hypermap is an embedding of the complete bipartite graph Kn,n, where n is an odd prime power. We show that these surfaces, regarded as algebraic curves, are all defined over abelian number fields. We determine their orbits under the action of the absolute Galois group, their minimal fields of definition and in some easier cases their defining equations. The paper relies on group – and graph – theoretic results by G. A. Jones, R. Nedela and M. Škoviera about regular embeddings of the graphs Kn,n [7] and generalises the analogous results for maps obtained in [9], partly using different methods.

A comparison was made of six different methods of inoculation with Cercosporella herpotrichoidesFron on field plots of the spring barley variety Impala. All inoculation treatments produced significant differences in terms of disease incidence and grain yield compared with the uninoculated controls. Significant differences were found between treatments in terms of disease incidence, disease severity, mean yield/head and 1000 grain weights. The time of inoculation was also found to be significant. The earlier inoculation caused a reduction in yield of approximately 66 % compared with 50 % at the later inoculation. The application of these methods is discussed.

The systemic fungicide benomyl was used as a seed dressing and as a spray at two concentrations, 250 and 500 ppm, on the winter barley variety Pella. An additional treatment was a spray application of CCC at 500 ppm. All spray treatments were applied at growth stage 3–4. Without fungicide treatment, total yield in the inoculated plots was approximately 40% of that in the uninoculated plots. The 500 ppm fungicide-spray treatment significantly decreased incidence and severity scores of eyespot, the seed dressing being significant only for the latter. The seed dressing and 500 ppm spray treatments significantly increased mean yield/head, fertile tiller number and 1000 grain weight. All the fungicide treatments significantly increased total yield in the inoculated plots. There were no significant effects of CCC upon disease or upon yield, neither was there any interaction between benomyl and CCC.

The results of progeny tests of families of F1 and F2 selections derived from S 100 white clover are reported. The selection criterion was a high total nodule mass per plant coupled with an effective symbiosis with a known effective strain of Rhizobium trifolii. Selection for increased nodule volume produced a correlated increase in nodule number. F1 and F2 had significantly higher means than S 100 but F2 was not significantly higher than F1.

Scores for nodule mass showed a significant increase in F1 and a smaller but insignificant increase in F2. An estimate of the efficiency of nitrogen fixation on a unit-nodule basis indicated that as nodule size increased efficiency decreased.

Evidence is provided that T. ambiguum, in common with other legumes, responds to inoculation with an effective strain of Rhizobium both in the field and in the glasshouse. There were consistent differences between the responses of 2x, 4x; and 6x: chromosome races to inoculation. Grass plants grown alongside effectively nodulated T. ambiguum plants gave significantly higher yields than those grown with ineffectively nodulated plants. The higher percentage germination associated with inoculation may be due to an effect of the skim milk used as inoculum carrier.

We wish to thank Professor P. T. Thomas and Mr W. Ellis Davies of the Welsh Plant Breeding Station, for their interest and advice, and Professor A. H. Bunting, of Reading University, for reading and correcting the manuscript.

The inoculation of legumes is often carried out using skim-milk as the carrier for the nodule bacteria. Increased germination due to inoculation has often been reported but in this investigation the effects of the skim-milk and the bacteria have been separated. The results indicate that the early establishment of T. ambiguum was stimulated by the skim milk rather than the nodule bacteria. The mechanism of this effect is thought to be due to extra N present in the milk and possibly to an enhanced nitrogen-cycle in the inoculated soil and evidence is produced of increases in certain freeliving nitrogen fixing and nitrifying microorganisms.

Torrentispora fibrosa gen. sp. nov. (Ascomycota, Annulatascaceae) is described based on specimens from submerged wood collected from streams in Tai Po Kau Forest Reserve, Hong Kong. T. fibrosa is characterized by immersed to superficial ascomata with a peridium of black cells arranged in irregular rows, wide septate paraphyses, long cylindrical asci with a relatively massive refractive apical ring, and unicellular ascospores with a fibrillar sheath. Illustrations from light and scanning electron microscopy are provided. It is compared with species in the genus Annulatascus, from which it differs in ascoma peridium and ascospore sheath morphology, and with other aquatic ascomycetes possessing ascospores with a similar fibrillar sheath structure.

A new genus, Halorosellinia, is introduced to accommodate the lignicolous mangrove inhabitant Hypoxylon oceanicum. A detailed illustrated account of the teleomorphic and anamorphic states is given. Halorosellinia oceanica comb. nov., is compared with Stilbohypoxylon quisquiliarum and Nemania confluens (a reduced form of Nemania) and the reasons for introducing a new genus are discussed. Data on the ecology and geographical distribution of H. oceanica are presented.

The ultrastructure of the dimorphic ascospores of Mamillisphaeria dimorphospora are illustrated. The small brown ascospores differ from the larger hyaline ascospores in having a thick melanin layer in the ascospore wall. They are also 2–3 times smaller and do not germinate on PDA. The significance of these observations with respect to dispersal of aquatic fungi is discussed. The large hyaline ascospores may be morphologically adapted to dispersal in streams, while the smaller brown ascospores are thought to be adapted to aerial dispersal. The reasons for this are discussed. The method by which two spore types can be produced in separate asci in one ascoma is hypothesised.

Activity patterns of greater horseshoe bats Rhinolophus ferrumequinum were investigated at caves in Cheddar (south-west England) during the hibernation season. An ultrasound detector and datalogger were used to monitor and record the number of echolocation calls in a single cave. Activity of R. ferrumequinum remained largely nocturnal throughout winter, and the mean time of activity over 24 h was 88 to 369 min after sunset. There was an increase in diurnal activity from late May to early June, probably because bats remained active after foraging at dawn towards the end of the hibernation season. Visits to the cave did not increase bat activity. Cave air temperature reflected external climatic temperature, although there was variation in cave temperature and its range within and among caves. Individual R. ferrumequinum are usually dispersed in caves in regions where temperature fluctuations correlate with climatic variations in temperature. There was a positive correlation between the number of daily bat passes monitored by the bat detector and datalogger (= daily activity) and cave temperature. Nocturnal activity may be sometimes associated with winter feeding. Neither date nor barometric pressure had a significant effect on daily activity. Activity patterns largely reflected the findings from individual R. ferrumequinum studied by telemetry (Park, 1998), in that bat activity increased with cave and climatic temperatures, and the temporal pattern of activity remained consistently nocturnal throughout winter, starting at dusk.

A new genus of freshwater ascomycetes, Cataractisopora, with three new species: C. aquatica, C. appendiculata and C. viscosa, are described. These fungi occur on decaying wood and possess similar characteristics including coriaceous globose ascomata, wide septate paraphyses, cylindrical asci with a relatively massive refractive apical ring and ascospores with polar chambers and filamentous appendages. Appendage material accumulates within the polar chambers and, on release from the ascus, the ascospore appendage unfurls to form long threads. The appendage material is fibrillar at the ultrastructural level, and is derived from episporial projections at the ascospore tip. Although these three fungi are similar to species of Annulatascus, they are assigned to a new genus – Cataractispora based on their unique appendage ontogeny. Annulatascus bipolaris is also assigned to Cataractispora on the basis of its ascospore appendage ontogeny.

A new freshwater ascomycete Micropeltopsis quinquecladiopsis sp. nov. was collected on submerged twigs in a stream in Thailand. The fungus is described at the light microscope, scanning and transmission electron microscope level. Distinctive features are the appendaged 1-septate hyaline ascospores. The appendage arises as an outgrowth of the episporium from a basal stalk, then divides into five arms (three long and two short). The episporium and appendages are surrounded by an indistinct (at light microscope level) mucilaginous layer. The fungus is assigned to the Dothideales (Trichothyriaceae). Ascospore appendage ontogeny is compared with those of marine Ascomycota (Halosphaeriales).