Cortical and endosomal structure of the marine sponge Stelletta grubii

The fine structure of the marine astrophorid sponge Stelletta grubii is described for the first time. The following new data are presented: spongin is present, choanocyte chambers are diplodal, intercellular symbiotic bacteria are numerous and unequally distributed in the cortex and endosome, and collagenous fibril bundles are associated with lophocyte activity and are not elastic fibers. The cortex contains numerous fibril bundles, fewer symbionts, very few cells, and transitional zones with higher archeocyte density near the surface and endosome. Limited phagocytosis of the bacterial symbionts is observed. This species appears to be dioecious and oviparous. These observations suggest that the enigmatic species Chondrosia reniformis is closely related to S. grubii and that it should be placed within or near the astrophorids. The rhizoids of the red alga Phyllophora palmettoides penetrate the sponge tissue without eliciting the development of a structurally specialized contact zone in the sponge matrix or of a limiting epithelium.     

Long-path FTIR Measurements of Volatile Organic Compounds in an Industrial Setting

A long-path Fourier transform spectrometer was used to make measurements of volatile organic compounds in an industrial complex in New Castle, Delaware as part of the Superfund Innovative Technology Evaluation (SITE) program. These data are compared to data taken with a whole-air canister technique. To provide an effective comparison the canisters were transported along the path for a 32-min period. For each FTIR spectrum, 256 interferograms were co-added over a 4-mln period. Eight individual spectra were then co-added to obtain the comparison data.     

Sensitivities of Australian and New Zealand amphipods to copper and zinc in waters and metal-spiked sediments

The sensitivities of eight benthic amphipods, Chaetocorophium cf. lucasi, Corophium colo, Grandidierella japonica, Hyale crassicornis, Hyale longicornis, Melita awa, Melita matilda and Melita plumulosa, to copper and zinc in water-only and whole-sediment toxicity tests were compared. Whole-sediment tests used copper- (1300 mg/kg) and zinc- (4000 mg/kg) spiked sediments after equilibration for sufficient time to produce pore water and overlying water concentrations below the lowest observable effect concentrations of water-only exposures. Survival of adults (after 10 d) and juveniles (after 96 h), and the metal concentrations in the body tissues of adults, were determined at the end of the tests. Two epibenthic amphipods from the genus Melita were the most sensitive species to aqueous copper and zinc, with a 96-h LC50 value of 120 microg Cu/l for both M. awa and M. plumulosa juveniles, and a 96-h LC50 value of 640 microg Zn/l for juveniles of M. plumulosa. Juvenile amphipods (7-d old) were more sensitive than adult amphipods (>30-d old) in both water-only and whole-sediment tests, with adult-LC50/juvenile-LC50 ratios in water-only tests ranging from 1.2 to l.5 for copper and 1 to 1.4 for zinc. All species except C. colo, C. cf. lucasi and M. matilda were sensitive to the copper-spiked sediment, with survival between 14% and 74% of controls. Similarly, all species except C. colo and G. japonica, showed a response to the zinc-spiked sediment (26-81% of control survival). The epibenthic amphipods were more sensitive than the infaunal tube-dwelling amphipods and are recommended as test species.     

Exploring the links between natural resource use and biophysical status in the waterways of the North Rupununi, Guyana

The North Rupununi District in south-west Guyana is comprised of a mosaic of ecosystems, including savannas, wetlands and forests, and is home to the Makushi Amerindians, who depend on the waterways for their subsistence needs. With logging and mining seen as increasing threats to the region, it is necessary to look at methods for engaging stakeholders in monitoring the status of their natural resources. This paper presents the results of a pilot study carried out to investigate water use by the Makushi Amerindians, and collect baseline data on the hydro-morphological aspects of the waterways. Methods included informal interviews, the use of the River Habitat Survey (RHS), and water quality measurements. The results indicate the heavy reliance of the Makushi on the waterways for their daily lives, particularly on fishing. Although ponds and creeks are important sources of fish, the rivers provide much larger catches of a greater diversity of fish species, both in the wet and dry seasons. The physical characteristics of the water sources used by the Makushi are mainly associated with the surrounding habitat types: the savanna areas containing the more nutrient rich white-water rivers, and the tropical forest areas containing the less nutrient rich black-water rivers. This study indicates that at present there is no direct evidence of adverse impacts on the waterways used by the Makushi in terms of fish catches, habitat conditions and water quality. A monitoring scheme was set up using this study's outputs as a baseline from which any future changes can be compared. Further work is to be carried out over the next three years to produce monitoring and sustainable management procedures for the North Rupununi ecosystems, by linking the physical attributes of the environment to biodiversity and subsequently local livelihoods, and by building capacity of local stakeholders through training.     

Hard core drinking drivers

The term "hard core" has been used extensively over the past 15 years to identify persons who drink and drive regularly, typically at high blood alcohol levels. This article discusses how the term arose and clarifies what it means, both as a concept and in practice. It describes the characteristics of hard core drinking drivers and estimates their contribution to drinking driver trips, arrests, and crashes. It summarizes current knowledge and recommendations on the most effective means to affect their behavior and reduce their drinking and driving.     

The evolution and effectiveness of graduated licensing

This paper traces the history of graduated licensing, starting about the point in time when Pat Waller's paper on the genesis of the concept ends, and examines the extent to which graduated licensing has produced reductions in collisions. It concludes with some general observations about future research needs, anticipating several of the papers that follow.The evolution of graduated licensing is chronicled, beginning with the early and largely unsuccessful efforts to introduce it in the United States in the late 1970s, through the pioneering efforts in New Zealand, which resulted in the first truly graduated system in 1987, to Canada where the program was introduced 7 years later, to the United States where it has flourished in more recent years. This 25-year history lesson hopefully creates an appreciation for the somewhat torturous journey that graduated licensing has experienced in achieving acceptance among the public and policy-makers-a journey that is not yet over, as subsequent papers in the symposium will show. The proliferation of graduated licensing in recent years is a mixed blessing-the wider adoption of graduated licensing has been a very positive development, but the programs that have evolved are anything but homogeneous in structure or content. Although this is often necessary for various reasons, it is worrisome that some programs are graduated licensing in name only. This suggests that future efforts to promote graduated licensing must emphasize adherence to the fundamental risk reduction and multistage principles on which the concept is based. The paper also considers the extent to which graduated licensing achieves its objective of reducing collisions among those covered by the program. Understandably, most jurisdictions would not introduce graduated licensing until it was shown to be effective and this, to some extent, slowed the process of implementation. The obvious irony is that it could not be shown to be effective until it was introduced. Fortunately, as history demonstrates, some jurisdictions were prepared to try the system based on its very sound empirical rationale. And, their confidence has been rewarded. A growing body of research, which shows that graduated licensing has been associated with significant and substantial reductions in collisions, is briefly described. The paper concludes with some general observations designed to anticipate the papers that follow. First, it outlines questions that still remain unanswered about graduated licensing-why or how it works, with whom it works, and what features are most effective. Precise and unambiguous answers to these questions are essential for the design of a system that maximizes the potential for reducing collisions, injuries, and deaths. Second, it signals a note of caution on the limits of graduated licensing-it is important to recognize just how effective and beneficial this program is; it is equally important to recognize that it is not the sole panacea for the problem of collisions involving new drivers.     

Kriging for estimating spatial pattern of contaminants: Potential and problems

This paper discusses and illustrates the use of kriging techniques for estimating the spatial pattern of contaminants in environmental media, particularly soil. The assumptions underlying kriging are reviewed as are some advantages and disadvantages of the method. Lognormal kriging (kriging applied to logarithmic-transformed data) is illustrated using a set of radionuclide soil concentrations at a nuclear testing area on the Nevada Test Site. This example shows how lognormal kriging can be used to estimate average concentrations at points or for blocks of land, concentration contours over space, confidence bands about these contours, and radionuclide inventory in soil. The validity of kriging estimates depends on the accurate estimation and modeling of the spatial correlation structure of the phenomenon. Accuracy is especially important when lognormal kriging is used and estimates of means and their standard deviations are required in the original, untransformed scale. This paper illustrates the bias that can result when a changing correlation structure over space is ignored.Operated for the U.S. Department of Energy by Battelle Memorial InstituteWork supported by Nevada Applied Ecology Group, U.S. Department of Energy, Nevada Operations Office under Contract DE-AC06-76RLO 1830.