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161.
The aim of this study was to examine the effects of selenium on concentrations of metabolites and enzyme activities acting as antioxidant markers in liver and kidney of Siberian sturgeon Acipenser baeri. Sturgeons were fed selenium cysteine for 30 and 60 d at 1.25, 5, 20 mg Se kg−1. Selenium level in the control feed was 0.32 mg kg−1. Se concentration was measured in liver, kidney and muscle of every specimen. Sturgeon accumulated Se in tissues with a clear dose-response relationship and the highest Se concentration was recorded in liver. This outcome is lined up with the findings obtained on the antioxidant markers evaluated in both tissues, and in which a dose-response for several biomarkers was recorded in liver. The superoxide dismutase activity in Se-treated fish was generally induced, while catalase activity was lower in liver or unaltered in kidney. The concentrations of glutathione S-transferase, glutathione reductase and total glutathione responded differently for both tissues and were induced in a different way at both endpoints. No changes of glyoxalase I activity were noted for both Se-treated tissues, while for glyoxalase II enzyme in liver a dose-related pattern was found showing a reversible effect (decreased and increased counteractive response) only in the 5 mg kg−1 group. Moreover, the highest Se concentrations did not cause marked changes in malondialdehyde levels of liver and kidney. The enhancement of glutathione peroxidase activity in Se-treated sturgeon might have prevented the lipid peroxidation in both tissues, providing to the Siberian sturgeon a great defense ability versus the prooxidant effect of selenium.  相似文献   
162.
163.
Sperm competition (the competition among the sperm of different males for fertilization of the eggs of a female) has been suggested to be an important component of sexual selection, but no general assessment has been made of this proposition. We used a meta-analytic approach to assess the extensive literature on paternity (the proportion of offspring in a focal nest sired by an attending male) in birds based on allozyme and molecular techniques. The relative variance in male mating success was on average increased by a factor of 4.6 over the variance in apparent male success. Males with more extravagant secondary sexual characters had higher paternity in their own nests than less adorned males. There was a weak effect of male age being positively associated with paternity in own nests. Male body size measured as the length of wing and tarsus was weakly positively associated with paternity in own nests. Male survival prospect was positively associated with paternity in own nests. Polygynous males generally had decreased paternity of their broods compared to monogamous males. Paternity of the resident male decreased with increasing population density and breeding asynchrony. The intensity of paternity guards such as within-pair copulation rate and mate guarding were not significantly related to extra-pair paternity. Sperm competition was thus an important component of sexual selection by increasing the variance in male mating success, and by being associated with the expression of secondary sexual characters, in particular in dense and asynchronously breeding populations of birds. Received: 12 February 1998 / Accepted after revision: 31 May 1998  相似文献   
164.
The aim of this work was to elucidate the role of nitrate as a terminal electron acceptor on the biodegradation of NPEO. We have characterized the products of NPEO degradation by mixed microbial communities in anaerobic batch tests by means of HPLC, 1H NMR and GC–MS. Anaerobic degradation of NPEO was strictly dependent on the presence of nitrate. Within seven days of anoxic incubation, NP2EO appeared as the major degradation product. After 21 days, NP was the main species detected, and was not degraded further even after 35 days. Nitrate concentration decreased in parallel with NPEO de-ethoxylation. A transient accumulation of nitrite was observed within the time period in which NP formation reached its maximum production. The observed generation of nonylphenol coupled to nitrate reduction suggests that the microbial consortium possessed an alternate pathway for the degradation of NPEO, which was not accessible under aerobic conditions.  相似文献   
165.
Environmental Science and Pollution Research - It is important to establish the toxicity pesticides against non-target species, especially those pesticides used in commercial formulations....  相似文献   
166.
Birds of prey, owls and falcons are widely used as sentinel species in raptor biomonitoring programmes. A major current challenge is to facilitate large-scale biomonitoring by coordinating contaminant monitoring activities and by building capacity across countries. This requires sharing, dissemination and adoption of best practices addressed by the Networking Programme Research and Monitoring for and with Raptors in Europe (EURAPMON) and now being advanced by the ongoing international COST Action European Raptor Biomonitoring Facility. The present perspective introduces a schematic sampling protocol for contaminant monitoring in raptors. We provide guidance on sample collection with a view to increasing sampling capacity across countries, ensuring appropriate quality of samples and facilitating harmonization of procedures to maximize the reliability, comparability and interoperability of data. The here presented protocol can be used by professionals and volunteers as a standard guide to ensure harmonised sampling methods for contaminant monitoring in raptors.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01341-9) contains supplementary material, which is available to authorized users.  相似文献   
167.
Unusual products of the aqueous chlorination of atenolol   总被引:1,自引:0,他引:1  
The reaction of the drug atenolol with hypochlorite under conditions that simulate wastewater disinfection was investigated. The pharmaceutical reacted in 1h yielding three products that were separated by chromatographic techniques and characterized by spectroscopic features. Two unusual products 2-(4-(3-(chloro(2-chloropropan-2-yl)amino)-2-hydroxypropoxy)phenyl) acetamide and 2-(4-(3-formamido-2-hydroxypropoxy)phenyl) acetamide were obtained along with 2-(4-hydroxyphenyl) acetamide. When the reaction was stopped at shorter times only 2-(4-(3-amino-2-hydroxypropoxy)phenyl) acetamide and the dichlorinated product were detected. Tests performed on the seeds of Lactuca sativa show that chlorinated products have phytotoxic activity.  相似文献   
168.
Chemical and petrochemical wastewaters contain a host of contaminants that require different treatment strategies. Regulation of macropollutants and micropollutants in the final discharge from industrial wastewater treatment plants (WWTPs) have become increasingly stringent in recent decades, requiring many WWTPs to be upgraded. This article presents an analysis of a WWTP treating petrochemicals in Porto Marghera, Italy, that recently was upgraded following legislative changes. Because of strict legal limits for macropollutants and micropollutants and a lack of space necessary for a full-scale WWTP overhaul, the existing activated sludge tank was converted into a membrane biological reactor. The paper presents experimental data collected during a five-month investigation showing the removal rates achieved by the upgraded plant for macropollutants (particularly nitrogen compounds) and micropollutants (heavy metals and organic and inorganic toxic compounds).  相似文献   
169.
The house fly, Musca domestica L., a relevant sanitary pest, is mainly controlled by insecticides. However, an inappropriate use of chemicals may induce resistance, treatment efficacy decline and environmental damages. We evaluated toxicity of some organophosphates, pyrethroids, spinosad and neonicotinoids by topical applications on adults of a M. domestica strain (OcRo) collected from an intensive chicken farm in Northern Italy, in comparison to a susceptible strain (s-DBF). The OcRo strain exhibited higher levels of resistance (RR??) to four pesticides in comparison to s-DBF. Spinosad and imidacloprid had very low RR??, thus were still efficient in OcRo control. We also tested resistance to pesticides in OcRo after topical applications of synergistic compounds. Hydrolases were involved in phosphorganic detoxification and cytochrome P450 monoxygenases in that of pyrethroids. These results indicate that OcRo strain is now multiresistant to organophosphates and pyrethroids, and this should be considered for an environmentally safe pest management.  相似文献   
170.
To avoid environmental pollution and health problems caused by the use of traditional synthetic pesticides, there is a trend to search for naturally occurring toxicants from plants. Among the compounds discussed for anti-fungal and insecticidal activity, the natural extracts from garlic and horseradish have attracted considerable attention. The objective of this study is to determine the insecticidal and anti-fungal activity of Armoracia rusticana and Allium sativum L. extracts against larvae of Aedes albopictus (Skuse) and some pathogenic fungi. For the insecticidal test, horseradish and garlic extracts were prepared from fresh plants (cultivated in Emilia Romagna region) in a solution of ethanol 80 % and the two different solutions were used at different concentrations (for the determination of the lethal dose) against the fourth instar mosquito's larvae. The fungicidal test was carried out by the agar plates technique using garlic and horseradish extracts in a 10 % ethanol solution against the following organisms: Sclerotium rolfsii Sacc., Trichoderma longibrachiatum, Botrytis cinerea Pers., Fusarium oxysporum Schlecht. and Fusarium culmorum (Wm. G. Sm.) Sacc. The first results demonstrated that the horseradish ethanol extracts present only a fungistatic activity against Sclerotium rolfsii Sacc., Fusarium oxysporum Schlecht. and F. culmorum (Wm.G. Sm) Sacc. while garlic extracts at the same concentration provided a good fungicidal activity above all against Botrytis cinerea Pers. and S. rolfsii. A. rusticana and A. sativum preparations showed also an interesting and significant insecticidal activity against larvae of A. albopictus, even if horseradish presented a higher efficacy (LC?? value of 2.34 g/L), approximately two times higher than garlic one (LC?? value of 4.48 g/L).  相似文献   
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