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21.
Stomach contents of 687 orange roughy [Hoplostethus atlanticus (Collett, 1889)] from the Challenger Plateau, sampled in March, July and November 1984, were examined. The relative importance of different components of the diet was assessed using three feeding indices which combine, in different ways, percentage frequency of occurrence, percentage number, and percentage weight of prey categories. For both sexes, for all size classes and at any time of the year, the most frequent and abundant components of the diet were prawns, followed by fish, squid, amphipods and mysids. The main natant decapod families were Oplophoridae, Pasiphaeidae, and Sergestidae. Fish, mainly Chauliodontidae and Myctophidae, were the most important prey by weight. Most prey species were benthopelagic and mesopelagic organisms which move towards the surface at night. However, H. atlanticus can be caught by bottom trawl (between 750 and 1 200 m) during any 24 h period, and there was no evidence of vertical migration in search of their prey. When the fish grow in length, there is a transition in the diet from prawns, mysids, and fish, to prawns, fish and squid. Squid were not found in the stomach contents of fish smaller than 20 cm. These dietary changes may be linked to modifications in morphology with growth. The relative proportions of the main dietary items, and in particular the natant decapod families, varied with time of the year. Also, the stomach data seem to indicate an increasing importance of fish and squid in the diet in deeper water. H. atlanticus appears to be an opportunistic predator, consuming a wide variety of invertebrates and fishes. Our results provide evidence to support the notion that benthopelagic predators which consume vertically migrating mesopelagic fish, have an important role in the transfer of energy to the benthos.  相似文献   
22.
Two species of crustose brown algae (Ralfsiaceae) are discussed. Petroderma maculiforme is described from several Massachusetts collections and Porterinema fluviatile is described for the first time from North America. The known world-wide distribution of both species is cited, and data are given on their ecology, and vegetative and reproductive periodicities. The wide range of salinities from which plants of these species have been collected indicate that they are both euryhaline. Lithoderma lignicola Kjeliman (1883) is synonymized with Petroderma maculiforme (Wollny) Kuckuck (1897) and Porterinema marina Jaasund (1965) with. P. fluviatile (Porter) Waern (1952).Systematics-Ecology Program Contribution No. 196.  相似文献   
23.
The aim of this paper was to assess the endogenous release of lead from bone to blood, in 204 exposed subjects. resuming their duties after a 10-month strike in a primary lead smelter in 1991. In vivo 109Cd K X-ray Fluorescence (109Cd K XRF) was used to measure the bone lead concentration in tibia and calcaneus in the smelter, in 1994 and five years later. The 1994 data were used to derive the post-strike bone lead concentrations retrospectively from the significant association between bone lead and the cumulative blood lead index (CBLI). When a linear model was used to predict the current blood lead upon the level of lead in bone, structural analysis of the data produced slopes for tibia (2.0, 95% CI 1.66-2.54) and calcaneus (0.19, 95% CI 0.16-0.23) that were significantly higher than those predicted by the commonly used simple linear regression method, for tibia (0.73, 95%, CI 0.58-0.88) and calcaneus (0.08, 95% CI 0.06-0.09). This suggests that more lead than previously predicted by regression is released from bone to blood. Furthermore, the structural analysis of the data produced an estimation of the contribution of the bone lead stores to the bloodstream that was more consistent with the 1999 epidemiological data than did the regression estimation. Moreover, a non-linear relationship between tibia lead and blood lead was suggested from the assumption checking procedures for regression. When a non-linear regression model was fit to the data, the method produced estimates of important parameters in human lead kinetics, namely the blood lead saturation constant, showing a good agreement with current knowledge of lead metabolism. Finally, the likelihood of a non-linear bone lead release seems to be supported by the recently described dependence of the half-life of lead in bone on age and intensity of occupational exposure.  相似文献   
24.
Environmental Science and Pollution Research - Construction waste (CW) source reduction is a crucial strategy to address the sustainability issue of the construction industry. The economic benefit...  相似文献   
25.
Callaghan TV  Tweedie CE  Webber PJ 《Ambio》2011,40(6):555-557
Polar and alpine environments are changing rapidly due to increases in temperature, which are amplified in the Arctic, as well as changes in many local factors. The impacts on ecosystems and their function have potential consequences for local residents and the global community. Tundra areas are vast and diverse, and the knowledge of geographical variation in environmental and ecosystem change is limited to relatively few locations, or to remote sensing approaches that are limited mostly to the past few decades. The International Polar Year, IPY, provided a context, stimulus and timely opportunities for re-visiting old research sites and data sets to collate data on past changes, to pass knowledge from old to new generations of researchers and to document environmental characteristics of sites to facilitate detection and attribution of future changes. Consequently, the project “Retrospective and Prospective Vegetation Change in the Polar Regions: Back to the Future,” BTF, was proposed and endorsed as an IPY activity (project #512). With national funding support, teams of researchers re-visited former sites and data sets throughout the Arctic and some alpine regions. These efforts have amounted to a gamut of “BTF” studies that are collectively geographically expansive and disciplinary diverse. A selection of these studies are introduced and presented in the current issue together with a brief synthesis of their findings.  相似文献   
26.
Goal, Scope and Background Reducing occupant exposure to indoor mold is the goal of this research, through the efficacy testing of antimicrobial cleaners. Often mold contaminated building materials are not properly removed, but instead surface cleaners are applied in an attempt to alleviate the problem. The efficacy of antimicrobial cleaners to remove, eliminate or control mold growth on surfaces can easily be tested on non-porous surfaces. However, the testing of antimicrobial cleaner efficacy on porous surfaces, such as those found in the indoor environment such as gypsum board can be more complicated and prone to incorrect conclusions regarding residual organisms. The mold Stachybotrys chartarum has been found to be associated with idiopathic pulmonary hemorrhage in infants and has been studied for toxin production and its occurrence in water damaged buildings. Growth of S. chartarum on building materials such as gypsum wallboard has been frequently documented. Methods Research to control S. chartarum growth using 13 separate antimicrobial cleaners on contaminated gypsum wallboard has been performed in laboratory testing. Popular brands of cleaning products were tested by following directions printed on the product packaging. Results A variety of gypsum wallboard surfaces were used to test these cleaning products at high relative humidity. The results indicate differences in antimicrobial efficacy for the six month period of testing. Discussion Results for the six types of GWB surfaces varied extensively. However, three cleaning products exhibited significantly better results than others. Lysol All-Purpose Cleaner-Orange Breeze (full strength) demonstrated results which ranked among the best in five of the six surfaces tested. Both Borax and Orange Glo Multipurpose Degreaser demonstrated results which ranked among the best in four of the six surfaces tested. Conclusions The best antimicrobial cleaner to choose is often dependent on the type of surface to be cleaned of S. chartarum contamination. For Plain GWB, no paint, the best cleaners were Borax, Lysol All-Purpose Cleaner-Orange Breeze (full strength), Orange Glo Multipurpose Degreaser, and Fantastik Orange Action. Recommendations and Perspectives These results are not meant to endorse the incomplete removal of mold contaminated building materials. However, it is recognized that complete removal may not always be possible and solutions to control mold regrowth may contribute to reduced occupant exposure. Current recommendations of removal and replacement of porous building materials should be followed. It is not the intension of this discussion to endorse any product. Reporting on the performance of these products under the stated conditions was and remains the only purpose. ESS-Submission Editor: Dr. Lee Young (youngrisk@bresnan.net)  相似文献   
27.
Behavioral Ecology and Sociobiology - Individual animals across all taxa differ consistently in behaviour, i.e. they show personality traits. This inter-individual variability has significant...  相似文献   
28.
Measurements of aerosol particles in the air of an urban area in the UK have been made. Ambient air was sampled and the particulates measured after passing through a size selective PM10 inlet. Particle mass was measured using a Tapered Element Oscillating Microbalance (TEOM). Particle number and size distributions were obtained using an Electrical Aerosol Analyser (EAA) and an Aerodynamic Particle Sizer (APS). Measurements were also made of local meteorological parameters. Fine particle number concentrations were found to show better temporal agreement, including diurnal variation, with particle mass concentrations than the coarser particle number concentrations.  相似文献   
29.
Retrofitting existing housing stock to improve energy efficiency is often required to meet climate mitigation, public health and fuel poverty targets. Increasing uptake and effectiveness of retrofit schemes requires understanding of their impacts on householder attitudes and behaviours. This paper reports results of a survey of 500 Kirklees householders in the UK, where the Kirklees Warm Zone scheme took place. This was a local government led city scale domestic retrofit programme that installed energy efficiency measures at no charge in over 50,000 houses. The results highlight key design features of the scheme, socio-economic and attitudinal factors that affected take-up of energy efficiency measures and impacts on behaviour and energy use after adoption. The results emphasise the role that positive feedback plays in reinforcing pro-environmental attitudes and behaviours of participants and in addressing concerns of non-participants. Our findings have implications for the design and operation of future domestic energy efficiency retrofit schemes.  相似文献   
30.
Abstract

The disposal of digested sewage sludge on crop‐producing land appeals to municipalities as an option but may pose a hazard to human and animal health if the plant material contains elevated levels of some heavy metals. This paper reports the levels of cadmium in corn grain and stover for six years — three years with sludge applied annually and for three years after sludge applications were terminated. The cadmium concentration in corn grain from the sixth year was similar to values found in corn grown on non‐sludged plots. In corn stover fron treated plots the cadmium concentration was greater than from untreated plots. Our. study indicated that phytotoxic levels of cadmium did not exist even though elevated levels occurred in the corn stover.  相似文献   
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