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41.
The effect of cadmium on antioxidant responses and the susceptibility to oxidative stress in the hydrothermal vent mussel Bathymodiolus azoricus 总被引:1,自引:0,他引:1
Rui Company Angela Serafim Richard Cosson Lionel Camus Bruce Shillito Aline Fiala-Médioni Maria João Bebianno 《Marine Biology》2006,148(4):817-825
Hydrothermal vents are a unique environment of extreme physical–chemical characteristics and biological species composition.
Cd is a toxic non-essential metal present in high concentrations in the hydrothermal vent environment, contrary to those found
in marine coastal areas. Cd toxicity has been related, among other things, with reactive oxygen species production, even though
this is a non-redox metal. Bathymodiolus azoricus is a deep-sea Mytilid bivalve very common in the Mid Atlantic Ridge (MAR) hydrothermal vent fields and very little is known
about the antioxidant defence system in this specie. Because lethal Cd concentration in B. azoricus is unknown, the aim of this study was to assess the effects of a Cd concentration higher than that found in the hydrothermal
vents on oxidative stress biomarkers, such as antioxidant enzymes. Mussels were exposed to 100 μg l−1 Cd during 24, 48 and 144 h, respectively, in a pressurized aquarium (IPOCAMP). Superoxide dismutase (SOD), catalase (CAT),
glutathione peroxidases (GPx), total oxyradical scavenging capacity (TOSC), metallothionein (MT) and lipid peroxidation (LPO)
were measured in the gills and mantle of B. azoricus. The results indicate that gills are first affected by Cd toxicity. This may be due to different physiological functions
of the tissues and by the presence of thio and methanotrophic symbiotic bacteria in the gills. The SOD and CAT are inhibited
during the first day of exposure in the gills, although TOSC and MT concentrations were the same in control and exposed mussels.
In the mantle, enzymatic activation only occurred after 6 days, and no significant differences in MT concentrations were found
in the control and exposed mussels during the first day, as observed in the gills. 相似文献
42.
Lionel Jayanetti Paul Follett 《生态毒理学报》2004,(3):64-65
在世界的许多地区,竹子的栽培技术已经非常成熟.它的种类繁多用途广泛,早有详细记载.已经被确认的大约有1250种竹子、1500种传统用途.主要的使用者是农村的穷人,大概正是由于这个原因,竹子主要是被更大些的社区认可.作为一种材料资源,竹子还没有得到它应得的主流认可.…… 相似文献
43.
44.
The last century was marked by a high demographic revolution and the fast development of urban environments. Now, more than 50% of the world’s 7.5 billion humans live in cities. This change has often induced the degradation of environmental quality in urban areas. As a consequence, management policies are now fostering the ‘return of nature’ in cities, which, in turn, is requiring a better understanding of the ecology of urban environments. In particular, there is a need for a better knowledge on soil management because soils provide many functions in cities such as urban agriculture. Optimizing the diversity of soil-living organisms is essential to many environmental functions such as water depollution, biochemical cycles, fertility and carbon storage. However, few studies on the biological quality of urban soils have been performed so far. This article reviews actual knowledge on soil biological quality for urban management. The definition of urban soils is discussed, and we present services provided by soils. We also review modern methods and techniques to assess the biological quality of urban soils. Last, we suggest communication means to improve the consideration of soil quality in urban planning policies aimed at sustainable cities. 相似文献
45.
An alkaline extraction method has been developed for the determination of total sulfate in mine tailings containing secondary sulfate minerals formed by the oxidation of primary sulfides. Oxidized tailings were extracted with a 0.3 M NaOH solution at a liquid/solid ratio of 30 at room temperature for 16 h. The sulfate concentration in the extracts was determined by ion chromatography (IC). The coefficient of variation for sulfate determinations ranged from 1.9 to 3.2% for five tailings samples collected at two tailings impoundments. Mineralogical analysis of the tailings by scanning electron microscopy/X-ray energy dispersive spectrometry (SEM/EDS) demonstrated that the extraction of sulfate was complete, with the exception of extremely insoluble barite. The proposed method is simple, yields an accurate yet rapid measurement of sulfate, and involves a safer laboratory operation than conventional methods that make use of strong HCl acid solutions. Moreover, this method allows the specific measurement of sulfate in the extract, whereas conventional methods are generally limited to the measurement of total S by inductively coupled plasma atomic emission spectrometry (ICP-AES) due to the interference of chloride with sulfate in IC. 相似文献
46.
This paper studies the design of a mining concession contract as a multi-period adverse selection problem where production is the depletion of a non renewable resource. Compared with symmetric information, we show that overproduction is optimal in the terminal phase of the resource extraction program. Moreover, asymmetric information lengthens the contract duration but reduces the scarcity rent. 相似文献
47.
Matthieu Dussauze Lionel Camus Stéphane Le Floch Karine Pichavant-Rafini Perrine Geraudie Nathalie Coquillé Aline Amérand Philippe Lemaire Michael Theron 《Environmental science and pollution research international》2014,21(24):13779-13788
In this study, impact of dispersed oil on cardiac mitochondrial function was assessed in a key species of Arctic marine ecosystem, the polar cod Boreogadus saida. Mature polar cod were exposed during 48 h to dispersed oil (mechanically and chemically) and dispersants alone. The increase observed in ethoxyresorufin-O-deethylase activity and polycyclic aromatic hydrocarbon metabolites in bile indicated no difference in contamination level between fish exposed to chemical or mechanical dispersion of oil. Oil induced alterations of O2 consumption of permeabilised cardiac fibres showing inhibitions of complexes I and IV of the respiratory chain. Oil did not induce any modification of mitochondrial proton leak. Dispersants did not induce alteration of mitochondrial activity and did not increase oil toxicity. These data suggest that oil exposure may limit the fitness of polar cod and consequently could lead to major disruption in the energy flow of polar ecosystem. 相似文献
48.
Lionel Mabit Paul Martin Arsenio Toloza Vesna Zupanc 《Journal of environmental radioactivity》2010,101(10):854-863
The aim of the present study was to establish a reference site and its soil characteristics for use of fallout radionuclides in erosion studies in Slovenia. Prior to this study, no reference site and baseline data existed for Slovenia for this purpose. In the agricultural area of Gori?ko in East Slovenia, an undisturbed forest situated in Šalamenci (46°44’N, 16°7’E), was selected to establish the inventory value of fallout 137Cs and to establish a baseline level of multi-elemental fingerprint (major, minor, trace elements including heavy metals) and naturally occurring radionuclides in soils. A total of 20 soil profiles were collected at four 10 cm depth increments for evaluation of baseline level of 137Cs inventory. An exponential distribution for 137Cs was found and the baseline level inventory was established at 7300 ± 2500 Bq m−2 with a coefficient of variation of 34%. Of this mean present-day inventory, approximately 45% is due to the Chernobyl contribution.The physical degradation of soils through erosion is linked with biochemical degradation. This study introduces an approach to establishment of the naturally occurring radionuclide and elemental fingerprints baseline levels at a reference site which can provide comparative data to those from neighbouring agricultural fields for assessment of soil redistribution magnitude using fallout radionuclides. In addition, this information will be used to determine the impact of soil erosion processes and agricultural practices on soil quality and redistribution within agricultural landscapes in Slovenia. 相似文献
49.
Biodegradation rates of 2-methylisoborneol (MIB) and geosmin through sand filters and in bioreactors 总被引:8,自引:0,他引:8
Taste and odour (T&O) causing compounds, in particular, 2-methylisoborneol (MIB) and geosmin, are a problem for water authorities as they are recalcitrant to conventional water treatment. In this study, biological sand filtration was shown to be an effective process for the complete removal of MIB and geosmin, with removal shown to be predominantly through biodegradation. In addition, MIB and geosmin were also effectively degraded in batch bioreactor experiments using biofilm sourced from one of the sand filters as the microbial inoculum. The biodegradation of MIB and geosmin was determined to be a pseudo-first-order reaction with rate constants ranging between 0.10 and 0.58 d−1 in the bioreactor experiments. Rate constants were shown to be dependent upon the initial concentration of the microbial inoculum but not the initial concentration of MIB and geosmin when target concentrations of 200 and 50 ng l−1 were used. Furthermore, rate constants were shown to increase upon re-exposure of the biofilm to both T&O compounds. Enrichment cultures with subsequent community profile analysis using 16S rRNA-directed PCR-DGGE identified four bacteria most likely involved in the biodegradation of geosmin within the sand filters and bioreactors. These included a Pseudomonas sp., Alphaproteobacterium, Sphingomonas sp. and an Acidobacteriaceae member. 相似文献
50.
Karimi Battle Sadet-Bourgeteau Sophie Cannavacciuolo Mario Chauvin Camille Flamin Cyril Haumont Adeline Jean-Baptiste Vincent Reibel Aurélie Vrignaud Grégory Ranjard Lionel 《Environmental Chemistry Letters》2022,20(5):3265-3288
Environmental Chemistry Letters - The global production of biogas has increased threefold during the last decade to partly replace fossil fuels, yet biogas production by anaerobic digestion... 相似文献