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341.
Cell proliferation and apoptosis were investigated in tissues of two bivalve species, Arctica islandica from the German Bight (age of bivalves: 33–98 years) and Iceland (7–148 years) and Aequipecten opercularis from the English Channel (2–4 years). High proliferation rates (10% nuclei dividing) and apoptosis in tissues of A. opercularis were in line with high-energy throughput and reduced investment into antioxidant defence mechanisms in the scallop. In contrast,
cell turnover was slow (<1% nuclei dividing) in A. islandica and similar in mantle, gill and adductor muscle between young and old individuals. In the heart, cell turnover rates decreased
with age, which indicates less-efficient removal of damaged cells in ageing A. islandica. Cell turnover rates, mass specific respiration and antioxidant enzyme activities were similar in German Bight and Iceland
ocean quahog. Variable maximum life expectancies in geographically separated A. islandica populations are determined by extrinsic factors rather than by fundamental physiological differences. 相似文献
342.
Spoors JA Winger LA Siew LK Dessi JL Jennens L Self CH 《Journal of environmental monitoring : JEM》2002,4(6):917-921
To date, no ligand binding assay has been described for the carbamate herbicide asulam, although a variety of physical methods, dependent on pre-concentration of water samples, have been documented for its assessment. However, asulam is increasingly used in sensitive agricultural areas, and statutory regulations concerning its monitoring will undoubtedly become more stringent. Antibodies are optimal partners in ligand binding assays, but it is commonly understood by immunological researchers that where no antibody reactive with a particular antigen has yet been described, the immunogenicity of the antigen may be particularly restricted. By the expedient of employing a specialised approach to final immunisation with an asulam-protein conjugate, prior to the immortalisation of a specific anti-asulam antibody-producing cell, we have succeeded in generating a monoclonal antibody reactive specifically with asulam that can be configured in a convenient immunoassay. This antibody may be used flexibly in a number of ways: small sample volumes of 10 microl can be assessed to sensitivities of 4.35 x 10(-7) M (10 microg L(-1)) while avoiding discrepancies contributed by the assay matrix; this antibody-based assay can also be formatted to deliver sensitivities at levels stipulated by regulatory authorities (e.g., 4.35 x 10(-9) M or 0.1 microg L(-1)) directly from a water sample, without prior pre-concentration. 相似文献
343.
Although stable isotope ratios in animals have often been used as indicators of the trophic level and for the back-calculation of diets, few experiments have been done under standardized laboratory conditions to investigate factors influencing 15N and 13C values. An experiment using Nile tilapia [Oreochromis niloticus (L.)] was therefore carried out to test the effect of different dietary protein contents (35.4, 42.3, and 50.9%) on 15N and 13C values of the whole tilapia. The fish were fed the isoenergetic and isolipidic semi-synthetic diets at a relatively low level. 15N and 13C values of the lipid-free body did not differ between the fish fed the diets with different protein contents, but the trophic shift for N and C isotopes decreased with increasing protein accretion in the individual fish, for N from 6.5 to 4 and for C in the lipid-free body from 4 to 2.5. This is the first study showing the strong influence of the individual protein balance to the degree to which the isotopic signature of dietary protein was modified in tissue protein of fish. The extrapolation of the trophic level or the reconstruction of the diet of an animal from stable isotope ratios without knowledge of the individual physiological condition and the feeding rate may lead to erroneous results. 相似文献
344.
Results of on-site interviews with industrial personnel involved in hearing conservation programs (HCPs) show common deficiencies in personnel training and program implementation, reducing HCP effectiveness in protecting employees from occupational hearing loss. Audiometric data base analysis (ADBA) provides procedures which allow HCP ineffectiveness to be detected before many employees develop significant noise-induced hearing loss. If HCP procedures are corrected, based on ADBA results, then audiometry serves to prevent hearing loss rather than simply detecting its occurrence. The paper presents criterion ranges for ADBA procedure results as recommended by the ANSI S12.12 Working Group for Evaluation of HCPs. 相似文献
345.
We assessed the relationship between riparian management and stream quality along five southeastern Minnesota streams in 1995
and 1996. Specifically, we examined the effect of rotationally and continuously grazed pastures and different types of riparian
buffer strips on water chemistry, physical habitat, benthic macroinvertebrates, and fish as indicators of stream quality.
We collected data at 17 sites under different combinations of grazing and riparian management, using a longitudinal design
on three streams and a paired watershed design on two others. Continuous and rotational grazing were compared along one longitudinal
study stream and at the paired watershed. Riparian buffer management, fenced trees (wood buffer), fenced grass, and unfenced
rotationally grazed areas were the focus along the two remaining longitudinal streams. Principal components analysis (PCA)
of water chemistry, physical habitat, and biotic data indicated a local management effect. The ordinations separated continuous
grazing from sites with rotational grazing and sites with wood buffers from those with grass buffers or rotationally grazed
areas. Fecal coliform and turbidity were consistently higher at continuously grazed than rotationally grazed sites. Percent
fines in the streambed were significantly higher at sites with wood buffers than grass and rotationally grazed areas, and
canopy cover was similar at sites with wood and grass buffers. Benthic macroinvertebrate metrics were significant but were
not consistent across grazing and riparian buffer management types. Fish density and abundance were related to riparian buffer
type, rather than grazing practices. Our study has potentially important implications for stream restoration programs in the
midwestern United States. Our comparisons suggest further consideration and study of a combination of grass and wood riparian
buffer strips as midwestern stream management options, rather than universally installing wood buffers in every instance.
RID=" ID=" The Unit is jointly sponsored by the US Geological Survey, Biological Resources Division; the Minnesota Department
of Natural Resources; the University of Minnesota; and the Wildlife Management Institute. 相似文献
346.
The purpose of this paper is to analyse under what conditions, with respect to CO2 emission-reduction and biofuels-for-transport targets, the trading in the EU of CO2 credits and solid and/or liquid biofuels is cost-effective from the perspective of an optimisation energy systems model. We use the PEEP model covering the EU27 (except Bulgaria, Malta, and Cyprus) to generate insights about the cost-effectiveness of different options under different policy scenarios. Trade in CO2 credits is a cost-effective option, in all relevant policy scenarios. Trade in some biofuels (mainly from central and eastern European countries to the EU15) is cost-effective in all assessed scenarios. In the case of CO2 targets (whether national or at the EU level) there is trade in solid biofuels. When biofuels-for-transport targets are also implemented, trading both solid and liquid biofuels is cost-effective. 相似文献
347.
Galchenko Alexey Vladimirovich Sidorova Elizaveta Ilinichna Sherstneva Anastasia Alekseevna Skalny Andrew Anatolevich Lobanova Julia Nikolaevna 《Environmental science and pollution research international》2022,29(6):8341-8352
Environmental Science and Pollution Research - Due to the development of the metallurgical and energy industries and the operation of incinerators, more and more environmental pollution is... 相似文献