Chemical trail communication in the amblyoponine species Mystrium rogeri Forel (Hymenoptera, Formicidae, Ponerinae)

Summary. Workers of the amblyoponine species Mystrium rogeri employ trail communication during recruitment to food sources and new nest sites. The trail pheromone originates from a hitherto unknown sternal gland located in the 7th abdominal sternite. The recruiting ant deposits the gland secretions by a special gaster-dragging behavior. The recruitment behavior can be complemented by a rapid vertical body shaking performed by some recruiting ants inside the nest. M. rogeri workers possess a large pygidial gland, the secretion of which elicits a repellent response in other ant species. Received 25 May 1998; accepted 15 June 1998.     

Utilisation of phosphorus nutrient content in industrial scale plasmid DNA production: a waste minimisation study

Human gene therapy is currently seeing an increase in the use of plasmid (pDNA)-based vectors as a preferred choice of vehicle for delivery of the therapeutic gene into the body. In this regard, the environmental impacts of the waste streams from the possible industrial scale manufacture of pDNA require more detailed assessment. In this study, an initial assessment was made of the nutrient phosphorus (P) inputs to four fermentation processes recommended for the industrial scale production of pDNA for the purposes of gene therapy. Phosphorus inputs to each of the four selected fermentation processes ranged from approximately 60 mg l^?1 up to 3000 mg l^?1 in the fresh media. However, the spent media waste from each of the processes exhibited only a minor reduction in the phosphorus concentrations indicating minimal uptake of P by the microorganisms. This unutilised excess level of phosphorus nutrient within the waste streams poses a strong potential for environmental impact. Waste minimisation studies were undertaken on one model fermentation process with the aim of reducing unnecessary phosphorus input. An optimised media containing a 98% reduction in added P to the media was developed. This phosphorus-minimised media had little quantitative effect upon cell biomass produced and no effect upon the quantity or quality of pDNA produced, relative to the control media. The reduction in P requirement results in an overall cost savings of 12% per fermentation batch, would simplify subsequent wastewater treatment and would contribute to slowing the depletion rate of a valuable, finite natural resource.     

Ten ways remote sensing can contribute to conservation

In an effort to increase conservation effectiveness through the use of Earth observation technologies, a group of remote sensing scientists affiliated with government and academic institutions and conservation organizations identified 10 questions in conservation for which the potential to be answered would be greatly increased by use of remotely sensed data and analyses of those data. Our goals were to increase conservation practitioners’ use of remote sensing to support their work, increase collaboration between the conservation science and remote sensing communities, identify and develop new and innovative uses of remote sensing for advancing conservation science, provide guidance to space agencies on how future satellite missions can support conservation science, and generate support from the public and private sector in the use of remote sensing data to address the 10 conservation questions. We identified a broad initial list of questions on the basis of an email chain‐referral survey. We then used a workshop‐based iterative and collaborative approach to whittle the list down to these final questions (which represent 10 major themes in conservation): How can global Earth observation data be used to model species distributions and abundances? How can remote sensing improve the understanding of animal movements? How can remotely sensed ecosystem variables be used to understand, monitor, and predict ecosystem response and resilience to multiple stressors? How can remote sensing be used to monitor the effects of climate on ecosystems? How can near real‐time ecosystem monitoring catalyze threat reduction, governance and regulation compliance, and resource management decisions? How can remote sensing inform configuration of protected area networks at spatial extents relevant to populations of target species and ecosystem services? How can remote sensing‐derived products be used to value and monitor changes in ecosystem services? How can remote sensing be used to monitor and evaluate the effectiveness of conservation efforts? How does the expansion and intensification of agriculture and aquaculture alter ecosystems and the services they provide? How can remote sensing be used to determine the degree to which ecosystems are being disturbed or degraded and the effects of these changes on species and ecosystem functions?     

The backward incidence of pollution control—some comparative statics in general equilibrium

The backward incidence of stronger pollution controls onto the factors of production is examined in a two sector (one polluting, one not), general equilibrium model. The real returns to labor and capital are found to move in opposite directions that depend on the factor intensity of the nonpolluting sector. The magnitudes of these effects are shown dependent upon the degree of factor intensity in that sector, the ease with which pollution can be removed from the effluent, the ease with which capital and labor can be substituted in either sector, and the price elasticities of demand for the sectors' products.     

A drowned Mesozoic bird breeding colony from the Late Cretaceous of Transylvania

Despite a rapidly improving fossil record, the reproductive biology of Mesozoic birds remains poorly known: only a handful of undisputed, isolated Cretaceous eggs (some containing embryonic remains) are known. We report here the first fossil evidence for a breeding colony of Mesozoic birds, preserved at the Late Cretaceous (Maastrichtian) Oarda de Jos (Od) site in the Sebe? area of Transylvania, Romania. A lens of calcareous mudstone with minimum dimensions of 80?cm length, 50?cm width and 20?cm depth contains thousands of tightly packed, morphologically homogenous eggshell fragments, seven near-complete eggs and neonatal and adult avialan skeletal elements. Eggshell forms 70–80?% of the matrix, and other fossils are entirely absent. The bones exhibit clear characters of the Cretaceous avialan clade Enantiornithes, and the eggshell morphology is also consistent with this identification. Both taphonomy and lithology show that the components of this lens were deposited in a single flood event, and we conclude that it represents the drowned remains of a larger enantiornithine breeding colony, swamped by rising water, washed a short distance and deposited in a shallow, low-energy pond. The same fate often befalls modern bird colonies. Such a large concentration of breeding birds suggests aquatic feeding in this species, augments our understanding of enantiornithine biology and shows that colonial nesting was not unique to crown birds.     

Ecology and Conservation of the Endangered American Burying Beetle (Nicrophorus americanus)

Field studies were conducted on the western population of the endangered American burying beetle (Nicrophorus americanus) in Oklahoma and Arkansas to determine its habitat affinities. A common cause of declining populations is some specialized adaptation that makes it difficult to respond to a rapidly changing habitat. We evaluated the hypothesis that N. americanus is a habitat specialist in its search for food, preferring mature forests with deep, humic soils. This hypothesis was rejected. Based on comparisons of niche breadth among syntopic congeners and niche overlap, N. americanus is relatively generalized in its use of a range of habitats when searching for food. It is likely that the generalist nature and the endangered status of N. americanus both derive from the fact that it is the largest member of its guild. In comparison to smaller species, N. americanus breeds on larger carcasses, which are more unpredictable in space and time. It is likely, therefore, that N. americanus must search over a larger area and greater diversity of habitats than its smaller congeners.