Digestive mechanics and gluttonous feeding in the feather starOligometra serripinna (Echinodermata: Crinoidea)

The movement and digestion of food in the gut ofOligometra serripinna (Carpenter) were studied at Lizard Island (14°3842S; 145°2710E) in the austral winter of 1986. Feather stars in the laboratory were fed a brief, small meal of brine shrimp nauplii and killed at increasing time intervals thereafter. Histological reconstructions showed that the ingested nauplii progressed along the digestive tract surprisingly quickly. Some nauplii were found in the mid and hind intestine in only 30 min, and all of the nauplii had reached the hind intestine and rectum in 1 h. Digestion of the nauplii had started at 1 h, and only a few fragments of naupliar exoskeleton remained in the hind intestine and rectum 5 h after the start of feeding. Videotape analysis showed that no fecal pellets were released during this experiment. In the natural environment ofO. serripinna, ingested particles may similarly be transported quickly to the hind part of the gut and digested there — when feather stars were fixed in the field, most of the gut contents were found in the hind intestine and rectum.O. serripinna, which efficiently rejects inert particles before they are ingested, usually defecates infrequently (probably not more than once over a span of many hours) and differs from some other feather stars that ingest numerous inert particles and defecate much more frequently. When specimens ofO. serripinna were fed continuously on brine shrimp nauplii,Artemia sp. (San Francisco strain), in the laboratory, the feather stars fed gluttonously, packing their guts with several hundred nauplii in 1 to 2 h. Thereafter, superfluous feeding began (i.e., further ingestions appeared to force undigested nauplii, some of them still living, out of the anus). These observations suggest thatO. serripinna usually feeds at relatively modest rates in its natural habitat, but can feed gluttonously to take advantage of infrequent patches of highly concentrated, nutritious particles (e.g. copepod swarms, migrating demersal zooplankton, and invertebrate gametes from mass spawnings). It is likely that such patches of nutritious particles are usually small enough to drift out of reach of the feather stars before gluttonous feeding proceeds to superfluous feeding. Opportunities for superfluous feeding in nature are probably very infrequent (e.g. ingestion of coral gametes and embryos after a mass spawning), and the feather stars evidently have no behavior that stops further ingestions after the gut becomes filled to capacity.     

Population monitoring for genetic damage induced by environmental physical and chemical agents

The short-term tests performed in vitro on different systems, from phage to human cells, or in vivo, on laboratory animals, allow only a qualitative estimate of the action of mutagenic agents, and the extrapolation of such experimental results to man may encounter many difficulties.Direct biomonitoring of populations exposed to chemicals could represent a more realistic approach for an evaluation of the hazards to man. Certain methods are still under development. Nevertheless, other ones can already by used routinely, e.g. the cytogenetic observations on peripheral blood lymphocytes and the Ames test for mutagenic substances in urine, and can provide useful suggestions how to set threshold limits for chemical substances encountered in the working environment.     

Analysis of a system for remote, dry removal of solidified mixed waste

This paper describes a novel technology for the removal of solidified radioactive waste from underground storage tanks at the DOE Hanford site in southeast Washington. The process involves the use of a unique high pressure system which pulverizes the hardened saltcake with stainless steel pellets to a powder for easy vacuum removal. The steel pellets can be magnetically separated from the waste material for re-use. Specifically this study analyzes the effects of various steel abrasives, pressure of the air stream, and stand-off distance on removal rates and penetration depth on simulated saltcake samples using the high pressure technique. A full-scale test set-up and protocol were implemented to allow for comprehensive testing. To insure reproducibility of the method, tests were then run for the optimum removal parameters. A time-dependent test was also conducted to determine the relationship of removal rates to length of pressure blasts. The results of these tests revealed that stand-off distance and pressure could be positively correlated to removal volumes. Additionally, a statistical analysis confirmed that nozzle angle is independent of removal rate. This study demonstrated that the pellet ‘blaster’ technique is a safe, effective method for removal of radioactive wastes without any increase in either waste mass or volume.     

Aboriginal world views and colonisation: implications for coastal sustainability†

In this paper, we show how the Aboriginal people in the south-west of Australia (the Nyungar) developed systems of knowledge, of caring for country and of family relations that enabled them to survive for tens of thousands of years and continue to have importance today. The impacts of British colonisation on cultural continuity and knowledge in the south-west have been significant and include loss of land, break-up of families and massacre. These practices led to a loss of knowledge of language and culture in some cases. However, Nyungar culture is alive and dynamic, constantly being reclaimed, re-energised and rebuilt through the interaction of contemporary and traditional research praxis. Focusing on Derbal Nara (Cockburn Sound) on the coast in the southern metropolitan area of Perth, we provide case examples of the action-research-learning methodologies used by Whadjuk Nyungar Traditional Owners. We also provide examples of stories about Derbal Nara that are still alive and being recounted up to the present day, including those that account for the recent ice age and the end of the ice age 8000 years BC when sea levels rose, drowning land in the area of Derbal Nara. Finally, we argue that Whadjuk Nyungar experiences and world views based on relationality and reflexivity are central to sustainable coastal management and that in some respects there has already been a convergence of Indigenous and Western coastal management. We present a set of principles that support the development of this “third space” for coastal sustainability.     

Pedestrian fatalities, Atlanta Metropolitan Statistical Area and United States, 2000-2004

Motor vehicle crashes killed almost 5,000 pedestrians in 2005 in the United States. Pedestrian risk may be higher in areas characterized by urban sprawl. From 2000 to 2004, pedestrian fatality rates declined in the United States, but the Atlanta metropolitan statistical area did not experience the same decline. Pedestrian fatality rates for males, Hispanics, and the 15–34 and 35–54 year age groups were higher in Atlanta than in the United States overall. Pedestrian safety interventions should be targeted to high-risk populations and localized pedestrian settings.     

Some Effects of Atmospheric Fluoride on Plant Metabolism

Leaves of Tendergreen bean plants exposed to atmospheric fluoride concentrations in the range 1.7 to 7.6 μg/m³ showed increased levels of enolase and catalase activity and decreased levels of pyruvate and α-ketoglutarate. Phosphoenolpyruvate carboxylase activity and oxalacetate were not affected. The leaves of Milo maize plants exposed to 5.0 μg F/m³ showed increased levels of enolase and pyruvate kinase activity and a decreased level of pyruvate. Oxalacetate and α-ketoglutarate levels were not affected. Catalase activity was increased, then decreased by IIF fumigation. The changes induced by HF were greatest six to 10 days after the start of fumigation and disappeared or decreased in magnitude during the post-fumigation period.     

Ambient Air Monitoring for Sulfur Compounds

The role of sulfur compounds in our environment has been the subject of much speculation during the past two decades. An evaluation of the effect of man-made contributions to the biogeochemical sulfur cycle requires a comprehensive examination of source magnitudes, atmospheric concentrations and removal processes. Many voids exist in our present knowledge of these parameters despite the contributions of numerous researchers. Adequate information is needed concerning the various forms of sulfur as well as other critical constituents which exist in our biosphere so that their interrelationship and role in the mechanisms of the sulfur cycle may be more fully understood.     

Effects of Fluoride on Agriculture

The effects of atmospheric fluorides on plants are summarized with respect to the level of biological organization at which they occur. The factors that determine the occurrence and degree of these effects are reviewed briefly. A series of economic effects on agriculture is postulated and its possible relationship to the botanical effects of fluorides is discussed.     

Long Range Cloud Diffusion in the Lower Atmosphere

Previous attempts to measure heavy metals in air are discussed with particular reference to lead. A polarographic method was developed for lead in air samples taken on glass fiber sheet. Using this method, the distribution of lead across the glass fiber sheet was investigated, and within experimental error, found to be uniform. Air samples from 18 Ontario cities, previously analyzed for benzo [a]pyrene content were analyzed.