Effects of a predator and prey on a foraging reef fish: implications for understanding density-dependent growth

A temperate reef-fish, magpie morwong Cheilodactylus nigripes , was more abundant in habitats (turfing algae) that supported larger numbers of prey at four different locations across >1000 km of continuous coastline. Cheilodactylus nigripes fed at greater rates in patches of turfing algae known to contain greater abundance of prey (primarily gammarid amphipods). In the presence of the piscivorous New Zealand fur seal Arctocephalus forsteri , however, these fish fed at a substantially reduced rate. These results have severe implications for understanding density-dependent growth. If predators are attracted to larger numbers of prey (this study) and prey suffer slower rates of growth under heavier predation risk (previous studies), then experiments that manipulate densities of prey to test the effects of competition may confound the effects of predators and competitors on growth. Separation of the density-dependent effects of foraging (predation) and rivalry over the acquisition of limited resources (competition) is needed.     

Genetic and biochemical analyses of protein II

We compared the structure of P.II proteins of gonococcal strain FA1090 by N-terminal sequence analysis of purified proteins and by DNA sequencing of cloned P.II genes. Regulation of P.II gene expression does not involve major DNA rearrangements, but may involve generation of frame-shifts in unexpressed P.II genes. There are probably 8 or 9 P.II genes, each possessing a common leader sequence, in the gonococcal chromosome.     

Discovery of novel benzo[b][1,4]oxazin-3(4H)-ones as poly(ADP-ribose)polymerase inhibitors

Structure based drug design of a series of novel 1,4-benzoxazin-3-one derived PARP-1 inhibitors are described. The synthesis, enzymatic & cellular activities and pharmacodynamic effects are described. Optimized analogs demonstrated inhibition of poly-ADP-ribosylation in SW620 tumor bearing nude mice through 24 h following a single dose.     

Interpretation of charcoal and pollen data relating to a late Iron Age ritual site in eastern Ireland: a holistic approach

The study of charcoal produced by five burning episodes that occurred in a rapid succession within a ritual pit dating to the late Iron Age at Raffin Fort, Co. Meath, Ireland, reveals considerable variation in the charcoal assemblages resulting from each burning episode. Wood selection processes are considered against the background of information on woodland composition and land-use history provided by a detailed pollen diagram from nearby Emlagh Bog, the chronology of which is based on both AMS ¹⁴C dates and tephra analysis. A human skull fragment lay on top of the charcoal layers but the radiocarbon evidence indicates that the skull predated the burnings by at least a century. This and other evidence indicate a ritual pit with the skull as a human relic. It is suggested that, in this instance, wood selection was neither random nor determined solely by availability or combustibility, but instead may have been informed by socio-religious belief systems pertaining to trees and wood. Early Irish documentary sources, which reveal a complex ethnography of wood and trees in later prehistoric and early historic Ireland, are reviewed. The results shed fresh light on aspects of late Iron Age archaeology in a part of Europe that was outside the direct influence of the Roman world. New information is provided on a distinctive feature in late Holocene Irish pollen records namely the Late Iron Age Lull (ca. a.d. 1–500). During this time, widespread regeneration of woody vegetation took place. In the subsequent early Medieval period renewed farming activity resulted in substantial decline in woodland, a pattern also seen at many other locations in Ireland.     

The association betweenCarpophilus beetles and cactus flowers

There is a close association between bowl-shaped cactus flowers and the nitidulid beetlesCarpophilus pallipennis (Say) andC. floralis Er. in North America. The nature of this association has not been clear. It now appears that the cactus flowers are brood sites of theCarpophilus beetles. The benefits in the association are one-sided, inasmuch as the beetles provide little or no pollination service for the flowers.Pollination of North American Cacti, VI.