Modification of shell formation in the giant clam Tridacna gigas at elevated nutrient levels in sea water

The effect on shell formation of Tridacna gigas by sea water supplemented for 3 mo with ammonium (5, 10 M, N) and phosphate (2, 5, 10 M, P), separately or in combination, was examined. Exposure to N and N+P significantly enhanced shell-extension rates, but significantly reduced shell weights at equivalent size. Scanning-electron microscopy further revealed structural alterations in the outer shell layer, such as misshapen aragonite crystals, irregular crossed-lamellar orientation, and relatively porous shell microstructure. These observations are consistent with results of X-ray diffractometry on the shells which show distinct shifts in the positions of reflections from the (012) and (200) crystal planes relative to the control, indicating changes in crystal lattice parameters following addition of nutrients.     

Control of Sitophilus oryzae infestation of stored wheat: An ecosystem model of the use of aeration

Populations of the grain storage insect pest Sitophilus oryzae (L.) may be controlled by manipulating the microclimates of grain bulks in which they occur. In this paper a validated mathematical model of the heat and moisture transfer phenomena that occur in aerated grain bulks is presented, and is combined with a population model of S. oryzae. The composite model predicts that blowing cold night air through grain bulks severely curtails the population growth of weevils. Furthermore, the composite model indicates that there is an optimum aeration strategy that results in the lowest number of insects. Aeration with ambient air is also shown to render the population dynamics of S. oryzae relatively insensitive to both initial grain moisture content and temperature. The results are discussed with reference to the physics of heat and moisture transfer between the air-water mixture and the hygroscopic grain.     

The Delphi approach to the mediation of environmental disputes

Environmental disputes, in many countries, have taken on a ritualistic character. Their persistence, even after prolonged analysis and debate, suggests that they result from ideological rather than factual differences. Since no single ideological position holds a monopoly on the truth, effective environmental management would seem to require an integration of views, the problem being how to achieve this. One approach to this problem is illustrated in this article. Two factions in the spruce budworm dispute in New Brunswick, Canada, were engaged in a mediation exercise using the Delphi method. Details of the design and execution of this form of mediation are provided, together with an evaluation of the Delphi's effectiveness in this context.     

How much geological detail is needed for gasifier success?

The incipient Underground Coal Gasification (UCG) industry in Queensland, Australia, undertook three trial projects in two Mesozoic basins of southeast Queensland. The experiences of these three operations provide useful retrospective insight into gasifier productivity. This paper identifies key output measures of gasifier ‘success’ including output gas composition, presence of contaminants in groundwater and consistency of chamber operation. Likewise, a review of the geological and hydrogeological understanding of each site prior to gasifier commissioning was undertaken. Productivity parameters from gasification were then correlated against the level of baseline geological/hydrogeological understanding for each site. The aim of the study was to identify the optimum scope of geological and hydrogeological understanding required at the site assessment phase to ensure safe, maximum gasifier output during production phase. This approach allows identification of poor or unexpected performance that is attributable to pre-existing uncertainty. A historical review of gasifier conditions inferred from the three trial projects is presented. Hence from the Queensland experiences it is possible to identify what aspects of baseline geological understanding should be clearly understood at the site selection phase in order to limit anomalous gasifier performance and undesirable deviations, and maximise production output.     

Complex rostral neurovascular system in a giant pliosaur

Pliosaurs were a long-lived, ubiquitous group of Mesozoic marine predators attaining large body sizes (up to 12 m). Despite much being known about their ecology and behaviour, the mechanisms they adopted for prey detection have been poorly investigated and represent a mystery to date. Complex neurovascular systems in many vertebrate rostra have evolved for prey detection. However, information on the occurrence of such systems in fossil taxa is extremely limited because of poor preservation potential. The neurovascular complex from the snout of an exceptionally well-preserved pliosaur from the Kimmeridgian (Late Jurassic, c. 170 Myr ago) of Weymouth Bay (Dorset, UK) is described here for the first time. Using computed tomography (CT) scans, the extensive bifurcating neurovascular channels could be traced through the rostrum to both the teeth and the foramina on the dorsal and lateral surface of the snout. The structures on the surface of the skull and the high concentrations of peripheral rami suggest that this could be a sensory system, perhaps similar to crocodile pressure receptors or shark electroreceptors.