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1.
During the 2001–2002 hydrological cycle, 8,000 tons P year−1 (44% as particulate phosphorus) originating from the Seine basin entered the Seine estuary. P content in suspended sediments
(SS) is 2.9 g P kg−1 (80% as inorganic form) at Poses (the upstream limit of the Seine estuary). During the transfer from Poses to Caudebec (the
limit of saline water intrusion), Particulate Inorganic Phosphorus (PIP) in SS decreases by 40% whereas Particulate Organic
Phosphorus (POP) remains stable. This decrease is explained as the result of (i) a dilution by SS poorer in P, originating
from storage zones (mudflats) within the estuary, and (ii) a loss of P by sedimentation, especially in the Rouen harbour where
15% to 20% of SS are yearly trapped and extracted. Downstream, in the turbidity maximum of the estuary, P content in SS is
twice as low as at Poses (1.5 g P kg−1, 70% as inorganic form). PIP content is fairly homogeneous both vertically and throughout an annual survey. On the other
hand, POP varies by season. Higher POP content is observed during vernal period with phytoplankton accumulation. In a salinity
gradient from 0 to 30 (PSS78), PIP content further decreases by 30%. POP does not vary much in this gradient, leading to the
assumption that PIP is submitted to desorption in response to the dilution by marine waters (poor in orthophosphates). Using
32P isotopic method, we establish a mathematical formulation of P exchangeable between the suspended solid and water phases
of the Seine estuary. Particulate P in the turbidity maximum zone is shown to represent a possible source of dissolved P,
available for algal growth in the Seine Bight. Instead of playing a role of nutrient retention, the turbidity maximum zone
of the Seine estuary could favour coastal eutrophication. 相似文献
2.
Assessing Nitrification and Denitrification in the Seine River and Estuary Using Chemical and Isotopic Techniques 总被引:4,自引:0,他引:4
Mathieu Sebilo Gilles Billen Bernhard Mayer Daniel Billiou Micheline Grably Josette Garnier André Mariotti 《Ecosystems》2006,9(4):564-577
Downstream from metropolitan Paris (France), a large amount of ammonium is discharged into the Seine River by the effluents
of the wastewater treatment plant at Achères. To assess the extent of nitrification and denitrification in the water column,
concentrations and isotopic compositions of ammonium (δ15N–NH4+) and nitrate (δ15N–NO3−, δ18O–NO3−) were measured during summer low-flow conditions along the lower Seine and its estuary. The results indicated that most of
the ammonium released from the wastewater treatment plant is nitrified in the lower Seine River and its upper estuary, but
there was no evidence for water-column denitrification. In the lower part of the estuary, however, concentration and isotopic
data for nitrate were not consistent with simple mixing between riverine and marine nitrate. A significant departure of the
nitrate isotopic composition from what would be expected from simple mixing of freshwater and marine nitrates suggested coupled
nitrification and denitrification in the water, in spite of the apparent conservative behavior of nitrate. Denitrification
rates of approximately 0.02 mg N/L/h were estimated for this part of the estuary. 相似文献
3.
Josette Garnier Aurélie Cébron Gaëlle Tallec Gilles Billen Mathieu Sebilo Anun Martinez 《Biogeochemistry》2006,77(3):305-326
The Seine River estuary (France) is the receptacle of a drainage basin characterised by high population density, heavy industrial
activity and intensive agriculture. Whereas nitrate concentrations are high due to diffuse sources in the upstream drainage
basin, ammonium mainly originates from the effluents of the Achères wastewater treatment plant (WWTP) downstream from Paris
and its suburbs (6.5 million equivalent-inhabitants). Ammonium is mostly nitrified in the tidal freshwater estuary and nitrification
causes a strong summer oxygen deficit. Average longitudinal summer profiles of oxygen and nitrogen concentrations for two
periods, between 1993–1997 and 1998–2003 in dry hydrological conditions (excluding the wet years 2000 and 2001) clearly reflect
the changes due to the improved treatment of wastewater from Paris and its suburbs. On the basis of daily water flux data
and twice monthly nitrogen measurements at the boundaries of the upstream freshwater estuarine section (108 km), we calculated
nitrification and denitrification fluxes, whose annual averages were 43 and 71 × 103 kg N d−1 respectively from 1993 to 2003, with summer values (July–September) representing 73 and 57% of the annual fluxes, respectively.
The degree of denitrification in the upper estuary appears to be closely related to the nitrification, itself more loosely
related to the amount of reduced nitrogen (Kjeldahl) brought by the treated effluents from the Achères WWTP. We estimated
the total N2O emissions to about 40 kg N d−1 (25–60 kg N d−1) in the same sector. 相似文献
4.
The River Seine, below Paris, receives the effluents from a large sewage treatment plant, increasing the ammonium concentration
up to 6 mgN.1− in late summer. Careful measurement of ammonium, nitrate and organic nitrogen during the downriver travel of the water masses
over 100 km below the outfall, along with direct determination of nitrification and benthic fluxes, allowed to establish a
budget of nitrogen transport and transformations in this reach of the river. Nitrification is shown to start after a distinct
period of several days required for the growth of a significant nitrifying bacterial population. Denitrification is active
in the upper layer of bottom sediments but absent from the water column. Comparison of our data with those published for the
period 1973–1976 shows that the nitrate load carried by the river has increased not only because of higher runoff of agricultural
nitrate in the upstream part of the watershed, but also as a result of the severe reduction in the rate of denitrification
processes, owing to the restoration of better oxygen conditions. 相似文献
5.
The food web in the lower part of the Seine estuary: a synthesis of existing knowledge 总被引:1,自引:0,他引:1
The Seine estuary illustrates the alterations to estuaries due to human activities heavy releases of pollutants of various origins and significant morphological changes beginning in the middle of the 19th century. The intertidal mudflat surface has been seriously reduced (< 30km2) since the channels of the Seine River came under management. While the role of the Seine estuary in the dynamics of the eastern English Channel ecosystem is recognized as important, the biological characteristics of the estuary remained relatively unknown until the 1990s. Biological diversity was progressively impoverished from the polyhaline zone to the oligohaline zone. In spite of a heavily contaminated environment, the macrobenthic and planktonic fauna of the Seine estuary remains similar to those of other northeastern Atlantic estuaries. The fauna exhibit clear contrasts between areas with very high abundance and others with very low abundance. The pelagic fauna, especially the copepod Eurytemora affinisand the shrimp Palaemon longirostris, are more abundant in the Seine estuary than in other estuaries. Diversified and abundant, Abra alba-Pectinaria koreni and Macoma balthica benthic communities occur, respectively, in the outer and inner parts of the estuary. In subtidal flats, benthic fauna is especially poor in terms of specific richness, abundance and biomass. Paradoxically, considering the high abundance of prey, fish are particularly scarce. Two food webs have been identified. In the oligohaline zone, where turbidity is maximum, the food web is exclusively planktonic, due to dredging that prevented benthic fauna from settling. In the polyhaline zone, fish populations that feed particularly on benthic fauna benefit from low turbidity and high oxygen concentrations. So, in spite of heavy organic and metallic contamination and human activities, the Seine estuary remains a highly productive ecosystem, which provides a nursery for marine fish and feeding grounds for migratory birds. A global management plan appears to be necessary in order to guarantee that the Seine estuary continues to function as it currently does. 相似文献
6.
A. Motelay-Massei D. Ollivon B. Garban K. Tiphagne-Larcher M. Chevreuil 《Hydrobiologia》2007,588(1):145-157
Measurements of polycyclic aromatic hydrocarbons (PAHs) were carried out from 2001 to 2003 in various environmental compartments
(ambient air, atmospheric deposition, soils, sediments, runoff, and surface waters) in the Seine Estuary. The goal of this
study was to identify the importance of atmospheric fluxes to occurrence of PAHs in the estuary, and to estimate the major
pathways of their transport and accumulation within this ecosystem. The annual atmospheric inputs in the estuary ranged from
2.5 to 16 kg for the first sampling year, which is high when compared to those calculated for other European locations. In
parallel, PAH transport from the atmosphere to the watershed outlet was investigated for two rural and urban small experimental
watersheds within the Seine Estuary. In rural areas, atmospheric inputs are higher than exported loads by surface water and
PAHs are accumulating in soils. The inverse occurs in urban areas, where the contribution of atmospheric deposition is negligible
compared with PAH exported loads by runoff. These results allowed us to establish a mass balance for PAHs on the scale of
the Seine Estuary, and to determine the dynamics of PAH transport. This study highlights the role of the atmospheric compartment
in the transfer of contaminants and the importance of the local PAH inputs within the Seine Estuary.
相似文献
A. Motelay-MasseiEmail: |
7.
The changes of dominance rank among female Japanese monkeys of the Koshima group over a period of 29 years from 1957 were
studied. The dominance rank order was relatively stable in the early population growing phase, while large scale-changes of
dominance rank order occurred successively in the phase of population decrease brought about by the severe control of artificial
feeding after 1972. Nevertheless, the rank order of several females of the highest status was stable. Furthermore, the reproductive
success of these highest status females was high (Mori, 1979a;Watanabe et al., in prep.). Divergence of the dominance rank order fromKawamura's rules (Kawamura, 1958) was observed in the following respects: (1) Some females significantly elevated their rank depending on the leader
males. (2) If mothers died when their daughters were still juveniles or nulliparous, the dominance rank of some of these offspring
females was significantly lower than the mother's one. However 55% of daughters which lost their mothers at a young age inherited
the mother's rank. (3) Dominance among sisters whose mother had died when at least one of the daughters was under 6 years
old followed the rule of youngest ascendancy in 60% (Kawamura, 1958), and in 80% when both of the daughters were nulliparous at the mother's death.
The mean rate of aggressive interactions for each female with subordinates to her was calculated by dividing the total aggressive
interactions between the female in question and her subordinates by the number of subordinate females to the female in question.
A female which showed a high rate of aggressive interactions with her subordinates was categorized as an “Attacker”, and a
female showing a lower rate was categorized as a “Non-attacker”. Similarly, categories of “Attacked”, and “Non-attacked” were
distinguished by using the rate of aggressive interactions with dominant females. Several females which were once categorized
in one category in a year were repeatedly categorized in the same category over different years. The “Attacked” tended to
be females of higher rank, and “Non-attackers” tended to be females of lower rank. “The second-higher-status females”, were
“Attacked”, and their rank was unstable. In particular, females of lower rank within the lineage of the highest rank suffered
this kind of severe status. Most of the daughters of these females showed a sharp drop of rank, and died when they were still
at a young age, i.e. “the second-higher-status females” displayed low fitness. “Non-attackers” were significantly “Non-attacked”;
i.e. they were females which showed a non-social attitude. Females which underwent a drop of rank tended to be “Non-attackers”.
The most important factor which determined the females' rank was the memory of their dominance relations under the influence
of their mother [dependent rank (Kawai, 1958)] in their early life during development. This finding corresponds well with the results in baboons obtained byWalter (1980); the target females of aggressive interactions by adolescent females were determined by the rank of the mothers when
these adolescent females were born. 相似文献
8.
Dieter Korn 《Pal?ontologische Zeitschrift》2003,77(2):445-470
The anti-Darwinian “Typostrophe Theory” of O.H.Schindewolf can be put to the test by revisiting the ammonoid examples on which this macroevolutionary model was founded. It is shown
that none of the three theoretical elements saltationism, internalism, and cyclism can be supported by empirical data obtained
from ammonoid research. Putative saltations (“Typogenesis”) were feigned because of the lack of knowledge of intermediate
forms. Internalistic and orthogenetic development (“Typostasis”) can only be favoured by neglecting possible functions of
morphological characters. Preprogrammed extinction of “degenerated” clades (“Typolysis”) is unlikely when ruling out anthropocentric
views regarding ammonoid morphology. In terms of evolution of Palaeozoic ammonoids, there is no basis for the preference of
the “Typostrophe Theory” or some of its composing elements, including the “Type Concept” and “Proterogenesis”, over the Darwinian
evolutionary model and the Modern Synthesis.
相似文献
9.
B. Thouvenin J. L. Gonzalez J. F. Chiffoleau B. Boutier P. Le Hir 《Hydrobiologia》2007,588(1):109-124
The Seine estuary (France) is currently one of the world’s most contaminated estuaries, due in particular to its high cadmium
and lead content. Proper understanding of contaminant transfer, transformation and retention mechanisms throughout the estuary
and up to the adjacent marine zone require a range of studies involving data collections, experiments, and modeling tool.
A multivariable transport model (SiAM-3D) was used to simulate dissolved and particulate transport and it is applied to several
calculation grids; a speciation model (MOCO) was used to select key species and obtain a schematic system representation.
The coupled model for Cd and Pb was compared with field measurements. The complementary character of various tools (model
applied to annual time scale, in situ measurements and experiments) allowed to explore and quantify various hypotheses on
the high dissolved cadmium concentrations observed during low river flow. The target is to achieve a compromise between acceptable
computing times and adequate result accuracy. Although particle and contaminant behaviour is globally well-reproduced by the
coarse grid, calculation errors relating to bayward fluxes and stocks deposited inside the estuary were highlighted after
comparison with the fine grid. 相似文献
10.
Richard W. Zabel James Faulkner Steven G. Smith James J. Anderson Chris Van Holmes Nicholas Beer Susannah Iltis Jared Krinke Gary Fredricks Blane Bellerud Jason Sweet Albert Giorgi 《Hydrobiologia》2008,609(1):289-300
Migratory fish populations are impacted worldwide by river impoundments. Efforts to restore populations will benefit from
a clear understanding of survival and migration process over a wide-range of river conditions. We developed a model that estimates
travel time and survival of migrating juvenile salmonids (Oncorhynchus spp.) through the impounded Snake and Columbia rivers in the northwestern United States. The model allows users to examine
the effects of river management scenarios, such as manipulations of river flow and spill, on salmonid survival. It has four
major components: dam passage and survival, reservoir survival, fish travel time, and hydrological processes. The probability
that fish pass through specific routes at a dam and route-specific survival probabilities were based on hydroacoustic, radio
telemetry, PIT tag, and acoustic tag data. We related reservoir mortality rate (per day and per km) to river flow, water temperature,
and percentage of fish passing through spillways and then fit the relationships to PIT-tag survival data. We related fish
migration rate to water velocity, percentage of fish passing through spillways, and date in the season. We applied the model
to two threatened “Evolutionarily Significant Units” (as defined under the US Endangered Species Act): Snake River spring/summer
Chinook salmon (O. tshawytscha Walbaum) and Snake River steelhead (O. mykiss Walbaum). A sensitivity analysis demonstrated that for both species survival through the hydropower system was responsive
to water temperature, river flow, and spill proportion. The two species, however, exhibited different patterns in their response.
Such information is crucial for managers to effectively restore migratory fish populations in regulated rivers.
Guest editors: R. L. Welcomme & G. Marmulla
Hydropower, Flood Control and Water Abstraction: Implications for Fish and Fisheries 相似文献
11.
Walter W. Ferguson 《Primates; journal of primatology》1992,33(2):273-279
In response to a critique byFerguson (1989),Leonard (1991) reiterates most of his original arguments for supporting “Australopithecus afarensis”Johanson, White, andCoppens, 1978 as a single species. He disregards the principle of morphological equivalence by comparing the dental metrics and morphology
of a hominid with those of species of the Pongidae, which do not correspond with the degree of variation in hominids, instead
of with those of species of the Hominidae. He fails to refute clear evidence that the range of variation of dental metrics
and morphology in “A. afarensis” exceeds that seen in species of the Hominidae. On the basis of extreme variation, “A. afarensis” is, therefore, interpreted as representing a composite species. 相似文献
12.
The effect of ammonia onl-glutamate (L-GLU) uptake was examined in cultured astrocytes. Acute ammonia treatment (5–10 mM) enhanced L-[3H]GLU uptake by 20–42% by increasing the Vmax; this persisted for 2 days and then started to decline. Ammonia, however, did not affect the uptake ofd-[3H]aspartate (D-ASP), a non-metabolizable analog of L-GLU, that uses the same transport carrier as L-GLU. Also, L-GLU uptake
was not affected during the first 2 min of the assay. Thus, ammonia did not have an acute effect on L-GLU transport (translocation);
rather, ammonia enhanced the accumulation or “trapping” of L-GLU or its by-products. Chronic ammonia treatment, on the other
hand, inhibited L-GLU transport in astrocytes by ∼30–45% and this was due to a decrease in Vmax, suggesting that the number of L-GLU transporters was decreased. This inhibitory effect was observed after 1 day of treatment
and persisted for at least 7 days. The inhibition of L-GLU transport was partially reversible following removal of ammonia.
The effects of ammonia on L-GLU transport and uptake may explain the abnormal L-GLU neurotransmission observed in hyperammonemia/hepatic
encephalopathy, and the brain swelling associated with fulminant hepatic failure. 相似文献
13.
Masayoshi Maehata 《Ichthyological Research》2001,48(3):283-287
The mating behavior of the rock catfish Silurus lithophilus (Siluriformes: Siluridae), a species endemic to the Lake Biwa system, was observed from May to July in 1989–1994 along the
rocky shore of the lake's outlet, the Seta River. The mating behavior of S. lithophilus involved a certain behavioral sequence: “chasing,”“clinging,” and “enfolding” while “squeezing” by the male; and “circling”
by the spawned pair. The mating behavior of this species was basically similar to that of S. biwaensis, but greatly different from that of S. asotus, which spawns in running water (in ditches). The mating behavior of S. lithophilus (and S. biwaensis) might have developed as an adaptation to lentic environments such as the shores of the large river or the lake.
Received: October 25, 2000 / Revised: February 25, 2001 / Accepted: March 8, 2001 相似文献
14.
[(4-methoxy-4(3-β-d-galactose-4-chlorophenyl)]spiro[1,2-dioxetane-3-1,3-tricyclo[7.3.1.02,7]tridec-2,7-ene] (“sβ-Gal 102”) and sodium [4-methoxy-4(3-β-d-glucuronic acid-4-chlorophenyl)]spiro[1,2-dioxetane-3-1,3-tricyclo[7.3.1.02,7]tridec-2,7-ene] (“sβ-Glucor 102”) are carbohydrate-containing 1,2-dioxetane compounds that produce chemiluminescence upon
enzymatic hydrolysis by β-d-galactosidase, and β-d-glucuronidase, respectively. In this study, we have characterized and validated a sensitive detection principle for viable
Escherichia coli based on enzymatic cleavage of sβ-Gal 102 and sβ-Glucor 102 (“ColiLight II”). The proposed chemiluminescent assay was optimized
with respect to analytical requirements including incubation time, temperature, pH, enzyme induction, and cell permeabilization.
The sensitivity and specificity rates of the assay were tested on ten different bacterial genera. The assay was found to be
representative based on low coefficients of variations for both accuracy and precision. The analysis time was less than 1 h
and the analytical detection limit was 102 to 103
E. coli cells. In combination with membrane filtration and a brief resuscitation step of 4 h, the proposed assay was capable of detecting
low concentrations of stressed E. coli in potable water (<30 CFU 100 ml−1). The proposed chemiluminescent enzyme assay may be used for assessing the metabolic activity of E. coli in oligotrophic environments and for early warning detection of low concentrations of E. coli in water for human consumption. 相似文献
15.
In view of antibiotics being detected in surface waters, experiments were conducted to determine the impacts of tetracycline
on planktonic bacteria in wetland and river waters. The minimum inhibitory concentration (MIC) method is often used to measure
for resistance or susceptibility of microbes to antibiotics with typical concentrations of antibiotics being mg L−1. Moreover, there is the belief that antibiotics in the lower μg L−1 range are unlikely to affect bacteria. We examined this assumption by measuring the effects of a broad range of tetracycline
concentrations on bacterial protein production by the incorporation of l-[4,5-3H]leucine method. Tetracycline significantly (P < 0.05) inhibited production in river water bacteria at a “free” concentration of 5 μg L−1, but the inhibition was significant only at 1000 μg L−1 in wetland water. The data indicate that planktonic bacteria can be very sensitive to tetracycline at extremely low concentrations
and that microbial production is seriously affected. 相似文献
16.
17.
Calcium-dipicolinate (Ca-DPA)-rich and Ca-DPA-deficientBacillus cereus spores were incubated in a synthetic medium with germination stimulants and in bactopeptone medium with a fairly high calcium
ion concentration. In the complex medium the germination of Ca-DPA-rich spores was completely blocked at a concentration of
0.5m CaCl2, whereas the complete blockage of germination in the synthetic medium required higher concentrations (0.6–0.8m) of calcium chloride. Ca-DPA-deficient spores germinated more slowly and less completely in the synthetic medium than in
the bactopeptone medium. The germination of these spores took place, however, even at higher calcium ion concentrations (0.6–0.8m). On the contrary, lower calcium chloride concentrations (0.1–0.4m) accelerated the germination of these spores in the synthetic medium and the final percentage of phase-dark and stainable
spores was higher. “H-forms” of the Ca-DPA-rich and Ca-DPA-deficient spores prepared by acid titration germinated in both
media. The germination of the latter spores being slower and proceeding less completely. “H-forms” germinated completely or
partially in media with a high concentration of calcium chloride. The percentage of germinated spores, however, was strongly
influenced by the concentration of this cation, especially the “H-forms” of Ca-DPA-deficient spores. Moreover, the germination
of Ca-DPA-deficient spores in this medium was affected by the length of previous storage and, in the case of “H-forms” by
the pH at which they were titrated. It was assumed that the increased permeability of calcium into the calciumundersaturated
spore periphery in Ca-DPA-deficient and in “H-forms” of spores of both types co-determines (in the presence of germinants)
the germinability of bacterial spores. 相似文献
18.
Four strains of the phytopathogenic bacteriumCorynebacterium fascians (Tilford)Dowson were selected from our isolates and deposited in the Czechoslovak National Collection of Type Cultures (CNCTC) of the Institute
of Hygiene and Epidemiology in Prague. Two very virulent (Cor 83/82 “UPR” and Cor 82/81 “UP”) and one avirulent (Cor 81/80
“CP1b”) pelargonium strains, producing acid from rhamnose, were isolated from fasciations onPelargonium zonale W. One avirulent celery strain ofC. fascians (Cor 80/80 “CF4a”) was isolated from a root expiant ofApium graveolens L. growing on a nutrient mediumin vitro. Morphological, cultural, physiological and biochemical characteristics of these selected Czechoslovak isolates were compared
with the American patented strain cotype ATCC 12974. 相似文献
19.
Fukuoka T Morita T Konishi M Imura T Sakai H Kitamoto D 《Applied microbiology and biotechnology》2007,76(4):801-810
Mannosylerythritol lipids (MELs), which are glycolipid biosurfactants produced by Pseudozyma yeasts, show not only excellent interfacial properties but also versatile biochemical actions. In the course of MEL production
from glucose as the sole carbon source, P. antarctica was found to produce unknown glycolipids more hydrophilic than conventional “di-acylated MELs,” which have two fatty acyl
esters on the mannose moiety. Based on a detailed characterization, the most hydrophilic one was identified as 4-O-(3′-O-alka(e)noyl-β-d-mannopyranosyl)-d-erythritol namely, “mono-acylated MEL.” The mono-acylated MEL reduced the surface tension of water to 33.8 mN/m at a critical
micelle concentration (CMC) of 3.6 × 10−4 M, and its hydrophilic–lipophilic balance was tentatively calculated to be 12.15. The observed CMC was 100-fold higher than
that of the MELs hitherto reported. Interestingly, of the yeast strains of the genus Pseudozyma, only P. antarctica and P. parantarctica gave the mono-acylated MEL from glucose, despite a great diversity of di-acylated MEL producers in the genus. These strains
produced MELs including the mono-acylated one at a rate of 20–25%. From these results, the new MEL is likely to have great
potential for use in oil-in-water-type emulsifiers and washing detergents because of its higher water solubility compared
to conventional MELs and will thus contribute to facilitating a broad range of applications for the environmentally advanced
surfactants. 相似文献
20.
Alberto C. Q. Pinto David H. Byrne Suzanne M. Dethier Rogers 《In vitro cellular & developmental biology. Plant》1993,29(2):55-58
Summary Ovule perforation technique and media components (plant growth regulators andl-glutamine) were tested on in vitro growth of immature (<3 mm) embryos of “Springcrest” and “Earligrande” peaches. Ovule perforation
was 2 to 4 times more effective in promoting embryo growth than leaving ovules intact.l-Glutamine (400 mg·liter−1) promoted an increase in growth but could not be used with indole-acetic acid plus kinetin because an antagonistic effect
on embryo growth occurred. The use of these exogenous plant growth regulators did not increase embryo growth over in vivo
growth. 相似文献