Activities of metabolic enzymes in the deep-water crabsChaceon fenneri andC. quinquedens and the shallow-water crabCallinectes sapidus

The activities of 18 enzymes were measured in gill, hepatopancreas and muscle tissue of the deep-water crabsChaceon fenneri andC. quinquedens and the shallow-water crabCallinectes sapidus collected from the Gulf of Mexico in January 1989. The activities of catabolic enzymes were correlated in general with the known metabolic rates of the three species. Activities were much higher inC. sapidus than inChaceon fenneri andC. quinquedens. In some cases,C. quinquedens had higher activities thanC. fenneri. The activities of enzymes of amino acid metabolism (glutamate dehydrogenase and alanine aminotransferase) were higher inC. quinquedens, which had high hemolymph [ammonia] and ammonia excretion rates. The activity of lactate dehydrogenase (LDH) ofC. fenneri andC. quinquedens were correlated with the two species' abilities to withstand hypoxia. The more hypoxiatolerant species,C. quinquedens, had higher activity of LDH in its muscles than didC. fenneri.     

The Potential Impact of Geophagia on the Bioavailability of Iron, Zinc and Calcium in Human Nutrition

Geophagia, the deliberate ingestion of soil, is a complex eating behaviour with obscure aetiology and numerous health/medical problems. It is conventionally assumed that geophagia may help supplement mineral nutrients in individuals with limited intake of trace elements such as Fe and Zn. This view, however, has largely been based on the bulk nutrient composition of geophagic materials and the assumption that these nutrients are potentially available for absorption in the body. We have tested this assumption by equilibrating five geophagic materials collected from Uganda, Tanzania, Turkey and India with mineral nutrient concentrations and conditions similar to the gastrointestinal tract. The results showed that all five geophagic materials, regardless of their composition, sorbed large amounts of Fe and Zn across a range of dietary intake scenarios, even under acidic conditions (pH 2) similar to the stomach. However, significant amounts of Ca desorption were observed from calcareous soil samples. The findings show that while calcareous geophagic materials may supplement Ca, geophagia can potentially cause Fe- and Zn-deficiency. This is consistent with mineral nutrient deficiency problems observed in clinical nutrition studies conducted amongst geophagic populations.     

Environmental Monotoring and Assessment Program: Current Status of Virginian Province (U.S.) Estuaries

Monitoring of indicators of the ecological condition of bays, tidal rivers, and estuaries within the Virginian Biogeographic Province (Cape Cod, Massachusetts to Cape Henry, Virginia) was conducted annually by the U.S. EPA's Environmental Monitoring and Assessment Program (EMAP) during the summer months of 1990 to 1993. Data were collected at 425 probability-based stations within the Province. Indicators monitored included water quality (temperature, salinity, water clarity, and dissolved oxygen concentration), sediment contamination, sediment toxicity, benthic community structure, fish community structure, and fish gross external pathology. Data were used to estimate the current status of the ecological condition of Virginian Province estuarine resources, and provide a baseline for identifying possible future changes. Estimates, with 95% confidence limits, of the areal extent of impacted resources within the Province are provided. Data are also presented by estuarine class (large estuaries, small estuarine systems, and large tidal rivers). Results show that, overall, approximately half of the estuarine waters of the Virginian Province can be classified as impacted based on multiple indicators, with hypoxia being the major stressor.     

Ultrastructural study and calcium and cadmium localization in the marine coccolithophoridCricosphaera elongata

Cells of the coccolithophoridCricosphaera elongata (Droop) Braarud (Prymnesiophyceae) were concentrated by means of tangential ultrafiltration. Ultrastructural features of control cells were typical of the genusCricosphaera. The flagellar apparatus consists of two flagella, a bulbous haptonema, an axosome and a basal helical band, as recently reported in the literature for another coccolithophorid. We observed a very-well developed Golgi apparatus, displaying all the features of the peculiar Golgi of the Prymnesiophytes. Observations with the light microscope did not reveal any difference between control algae and algae contaminated with 1, 10 and 20 µmol Cd 1^–1 (i.e., 112 µg 1^–1, 1.12 and 2.24 mg Cd 1^–1) for 48 h. However, algae treated with the highest cadmium concentration exhibited loss of motility after 6 h contact, but without apparent ultrastructural damage. Qualitative X-ray microanalysis of the dense granules present in Golgi vacuoles of control cells demonstrated the presence of calcium and chlorine and, at a lower level, sulphur and aluminium. The same elements were also identified in the dense part of the lysosomes. In situ,C. elongata produces coccoliths; this did not occur in culture. However, the coccolith-generating apparatus (Golgi complex and Ca²⁺) was present in culture, and the cells were able to synthesize unmineralized scales.     

Shoot biomass of turfgrass cultivars grown on composted waste

Various cultivars of four cool-season grass types (tall fescue, fine fescue, perennial ryegrass, and Kentucky bluegrass) were seeded in 0.34-liter plastic pots containing either composted sewage sludge [Com-Til² (CT), Soil Magic² (SM)] or composted yard mulch (YM). Plants were grown in the greenhouse for four weeks prior to measuring shoot biomass. White most tall fescue cultivars showed more shoot growth on YM, perennial ryegrass cultivars generally grew better on SM. Cultivars of fine fescue and bluegrass grew about the same on YM or SM, and slightly less on CT. With very few exceptions, shoot biomass of individual cultivars was greater on either YM or SM than it was on CT. Within individual grass types, Pennlawn (fine fescue), Pennant (perennial ryegrass), and Victa (Kentucky bluegrass) averaged consistently better growth on all three composted media. For tall fescue, Aquara, Rebel II, and Monarch performed best on YM, SM, and CT, respectively. Bioaccumulation of heavy metals did not occur in selective samples of shoot tissues collected from the grass types used. This research was supported by National Science Foundation grant #8902053 to Buckeye Bluegrass Farms. The greenhouse studies described in this paper were performed in conjunction with field tests conducted at Buckeye Bluegrass Farms. Requests for information on field trials should be directed to H. F. Decker, Box 176, Ostrander, Ohio 43061, USA. Use of trade names is for the reader's information only and does not imply endorsement over similar products of like properties.     

The relationship of beer consumption and state alcohol and motor vehicle policies to fatal accidents

Fatal accident data from 50 states and the District of Columbia were examined in order to determine the relationship between alcohol availability and fatal motor vehicle accidents. This relationship was analyzed for both fatal accidents and motor vehicle fatalities (potentially more than one per accident) using multiple regression. The independent variables were: (1) driving age (percent of drivers under 21); (2) beverage purchase age; (3) average beer consumption; (4) number of outlets per million population selling alcohol for on-premise consumption; (5) percentage of metropolitan residents; (6) percentage of male drivers; and (7) mileage per driver per year. It was found that the regression analyses for fatal accidents and for fatalities were highly similar. Driving age was the strongest predictor of highway mortality. On-premise availability of alcohol was significantly and inversely associated with motor vehicle fatalities. This suggests that when on-premise outlets are fewer and more geographically spread out, the chances of drinking and driving are greater. Finally, average beer consumption was significantly and positively associated with highway fatalities perhaps because many drivers consider it a “soft” alcoholic beverage that will not impair their ability to drive.     

A general agreement on commodity organization : A ‘GATT for primary commodities’

Having reponded to various crises since the Paris Sugar Convention 1864, the process of international commodity organization is now recognized as a positive means of securing expansion of world trade and of bringing about development in producing countries. But these objectives necessitate multi-dimensional measures. The supply-management techniques, hitherto the pivot of international commodity agreements, have proved to be inadequate. It is argued in this article that the trade and development objectives can be better achieved by the provision of varied measures; that a ‘GATT for primary commodities’ is among such measures; and that such an organization does not negate, but supplements, the existing system.     

Assessing representativeness of places for conservation reservation and heritage listing

Problems arising from application of the representative criterion for conservation and natural heritage evaluation are discussed. An ecological basis to this criterion is suggested that focuses on those key environmental factors dominating biotic response. A methodology is proposed that utilizes computer-based methods of establishing and interrogating spatial data bases (geographic information systems), environmental modeling, and numeric analysis. An example is presented illustrating some of the advantages and limitations of classification and dimension reduction techniques in both defining bioenvironments and displaying their spatial distribution. The advantages of this method for representativeness evaluation are that it maximizes the utility of available data, is explicit and repeatable, and enables large areas to be analyzed at relatively fine scales.     

Polychlorinated biphenyl (PCB) congeners and chlorinated pesticides in a cod liver oil reference material

A cod liver oil reference material, Standard Reference Material (SRM) 1588, which was issued by the National Institute of Standards and Technology (NIST) in 1989, has certified concentrations for five polychlorinated biphenyl (PCB) congeners and ten chlorinated pesticides. Recently, this SRM has been extensively characterized by additional analyses at NIST and by analyses at the Canadian Wildlife Service (CWS) where the SRM was used as a control sample during routine analyses of wildlife tissue specimens. In this paper the results from NIST and CWS are compared and the concentrations for over 40 PCB congeners and 20 chlorinated hydrocarbons are reported.     

Comparison of E. coli, enterococci, and fecal coliform as indicators for brackish water quality assessment.

Escherichia coli (E. coli), enterococci, and fecal coliform data were collected and compared as potential indicators for swimmablility assessment of a brackish waterbody (Lake Pontchartrain, Louisiana). These indicators were measured during lake background conditions, in stormwater runoff (before dilution with lake water), and in the outfall plume within the lake following storm events. Microbial indicator titers associated with suspended particles and lake-bottom sediments were also investigated. Overall reduction rate constants for fecal coliform, E. coli, and enterococci in lake water and sediment were measured and reported. Attachment of microbial indicators to suspended matter and subsequent sedimentation appeared to be a significant fate mechanism. A slower reduction rate of indicator organisms in sediment further suggested that bottom sediment may act as a reservoir for prolonging indicator organism survival and added concern of recontamination of overlaying waters due to potential solids resuspension. Results indicated that enterococci might be a more stable indicator than E. coli and fecal coliform and, consequently, a more conservative indicator under brackish water conditions.