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341.
Christine Pergent-Martini Gérard Pergent Eddy van der Maarel 《Journal of Coastal Conservation》2002,8(2):107-108
Two Special Features on integrated coastal zone management, especially along the Mediterranean Sea, result from a MeDCOAST
conference held in Hammamet (Tunisia). 20–25 October 2001. In this first Special Feature some papers are presented on ecological
and biological research related to integrated coastal zone management. All over Europe coastal environments are threatened
by human activities such as urbanization, industrial development, fisheries, aquaculture, recreation and tourism. Research
has to be developed that can be applied to similar case studies in different countries. Methods of monitoring are necessary
and baseline data have to be available in order to judge the significance of changes in the abjotic and biotic environment.
Examples of studies included in this Special Feature are mainly from southern banks of the Mediterranean Sea but there is
also an example from Estonia and one from the Canary Islands. 相似文献
342.
Response of zooxanthellae in symbiosis with the Mediterranean corals Cladocora caespitosa and Oculina patagonica to elevated temperatures 总被引:1,自引:0,他引:1
Riccardo Rodolfo-Metalpa Cécile Richard Denis Allemand Carlo Nike Bianchi Carla Morri Christine Ferrier-Pagès 《Marine Biology》2006,150(1):45-55
Scleractinian symbiotic corals living in the Ligurian Sea (NW Mediterranean Sea) have experienced warm summers during the last decade, with temperatures rapidly increasing, within a few days, to 3–4°C above the mean value of 24°C. The effect of elevated temperatures on the photosynthetic efficiency of zooxanthellae in symbiosis with temperate corals has not been well investigated. In this study, the corals, Cladocora caespitosa and Oculina patagonica were collected in the Ligurian Sea (44°N, 9°E), maintained during 2 weeks at the mean summer temperature of 24°C and then exposed during 48 h to temperatures of 24 (control), 27, 29 and 32°C. Chlorophyll (chl) fluorescence parameters [F
v/F
m, electron transport rate (ETR), non-photochemical quenching (NPQ)] were measured using pulse amplitude modulated (PAM) fluorimetry before, during the thermal increase, and after 1 and 7 days of recovery (corals maintained at 24°C). Zooxanthellae showed a broad tolerance to temperature increase, since their density remained unchanged and there was no significant reduction in their maximum quantum yield (F
v/F
m) or ETR up to 29°C. This temperature corresponded to a 5°C increase compared to the mean summer temperature (24°C) in the Ligurian Sea. At 32°C, there was a significant decrease in chl contents for both corals. This decrease was due to a reduction in the chl/zooxanthellae content. For C. caespitosa, there was also a decrease in ETRmax, not associated with a change in F
v/F
m or in the non-photochemical quenching (NPQ); for O. patagonica, both ETRmax and F
v/F
m significantly decreased, and NPQmax showed a significant increase. Damages to the photosystem II appeared to be reversible in both corals, since F
v/F
m values returned to normal after 1 day at 24°C. Zooxanthellae in symbiosis with the Mediterranean corals investigated can therefore be considered as resistant to short-term increases in temperature, even well above the maximum temperatures experienced by these corals in summer. 相似文献
343.
Christine Errard Francisca Ruano Freddie-Jeanne Richard Alain Lenoir Alberto Tinaut Abraham Hefetz 《Chemoecology》2006,16(4):235-240
Summary. Proformica longiseta exists as two populations in the Sierra Nevada Mountains in Spain, only one of which is parasitized by the slave-maker ant
Rossomyrmex minuchae. To investigate the possible effect of co-evolutionary pressures on cuticular hydrocarbon (CHC) profiles (the presumed nestmate
recognition cues), we performed a comparative analysis of the CHC of R. minuchae and P. longiseta colonies from both the allopatric and sympatric populations; the latter includes samples of enslaved as well as free-living
workers. Discriminant analyses based on these chemical profiles showed two clear profile groups: the first comprised R. minuchae and both enslaved and free-living P. longiseta from the sympatric population; and the second the allopatric P. longiseta workers. As expected, the profiles of the two sympatric P. longiseta groups (enslaved and free-living) were distinct; but, interestingly, those of the enslaved P. longiseta and its parasite R. minuchae were also distinguishable. This indicates that despite their cohabitation each species maintains its own chemical identity.
Profile similarity between the sympatric free-living P. longiseta and its parasite may explain the lower than expected aggression observed during raids. We further speculate that in view
of the differences between the sympatric and allopatric population of P. longiseta, co-evolutionary pressures have driven changes in the profile of the former to better match that of its parasite R. minuchae. Such an adjustment may have enabled nests of the sympatric P. longiseta to endure multiple raids by the parasite (due to the reduced aggression) and thus to continue to reproduce despite the damage
inflicted by the raids. 相似文献
344.
Freddie-Jeanne?RichardEmail author Abraham?Hefetz Jean-Philippe?Christides Christine?Errard 《Chemoecology》2004,14(1):9-16
Summary. Neotropical Fungus-growing leaf-cutting ants (tribe Attini) live in
obligatory symbiosis with a fungus, which they grow on fresh leaves harvested by
workers. Colonial recognition is likely based on chemical cues provided by cuticular
hydrocarbons that have been found to be partly influenced by environmental odor
sources. The diet breadth of Acromyrmex
subterraneus subterraneus enabled us to test
the impact of different plant diets on colonial recognition. The intermediary of the
fungus in the ants feeding habit adds a special angle to the question.
From a queenright (QR) mother colony of A. s. subterraneus
we formed several groups of queenless (QL) workers with fungus (approx. 700 ants). The QR
colony and two of the QL-groups were fed with the same diet of fresh bramble leaves. Two other
QL-groups were fed with privet leaves and two with rose flowers. After 4 months, QR workers were
significantly more aggressive towards the QL-group fed with rose flowers or privet
leaves than towards workers of the QL-groups fed with fresh bramble leaves. Rose-fed
QL workers were aggressive towards privet-fed QL workers and vice versa, but never towards
workers of their counterpart group that fed on the same diet. These results suggest
that the absence of the queen or the separation time between groups played a minor
role in shaping nestmate recognition cues as compared to the diet. The behavioral
studies were supplemented by chemical analyses of cuticles, postpharyngeal glands
(PPG) and plant-food extracts revealing profiles variations that were correlated
with the dietary changes. However, although the plant extract contained several
hydrocarbons there was no congruency between the plant profile and the respective
diet-group ants. These results support the hypothesis that the diet influences
indirectly the chemical profiles and consequently the recognition cues in
A. s. subterraneus. 相似文献
345.
Hawes AK Solomon S Portmann RW Daniel JS Langford AO Miller HL Eubank CS Goldan P Wiedinmyer C Atlas E Hansel A Wisthaler A 《Journal of environmental monitoring : JEM》2003,5(6):977-983
Measuring hydrocarbons from aircraft represents one way to infer biogenic emissions at the surface. The focus of this paper is to show that complementary remote sensing information can be provided by optical measurements of a vegetation index, which is readily measured with high temporal coverage using reflectance data. We examine the similarities between the vegetation index and in situ measurements of the chemicals isoprene, methacrolein, and alpha-pinene to estimate whether the temporal behavior of the in situ measurements of these chemicals could be better understood by the addition of the vegetation index. Data were compared for flights conducted around Houston in August and September 2000. The three independent sets of chemical measurements examined correspond reasonably well with the vegetation index curves for the majority of flight days. While low values of the vegetation index always correspond to low values of the in situ chemical measurements, high values of the index correspond to both high and low values of the chemical measurements. In this sense it represents an upper limit when compared with in situ data (assuming the calibration constant is adequately chosen). This result suggests that while the vegetation index cannot represent a purely predictive quantity for the in situ measurements, it represents a complementary measurement that can be useful in understanding comparisons of various in situ observations, particularly when these observations occur with relatively low temporal frequency. In situ isoprene measurements and the vegetation index were also compared to an isoprene emission inventory to provide additional insight on broad issues relating to the use of vegetation indices in emission database development. 相似文献
346.
The use of the gasoline additive methyl tert-butyl ether (MTBE) has caused serious concern about groundwater and surface water contamination. The behavior of MTBE in the two most relevant compartments, surface water and air in a generic environment and in a simulated German environment is investigated using the equilibrium criterion (EQC) model. Due to lack of literature data, the half-life time of MTBE in river water is estimated to about 80-120 d (105 d) at 18 degrees C and roughly 1.5 a (year)(533 d) at 4 degrees C from a batch experiment. The EQC model considers four compartments, air, surface water, soil and sediment in an environment of typically 100,000 km2 with about 10% of the area covered with water. The user can progress through the tiered sequence of Level I to III with increasing complexity which reveals more information about the the fate of the considered chemical. The equilibrium mass distribution of MTBE calculated with the Level I model shows that 87% partitions into air and 13% into surface water at 10 degrees C. The results of the Level II calculations indicate that 50% of MTBE in the air is transported from the system and 38% in the air is degraded at 10 degrees C. The resulting total persistence time of 3 d for MTBE in the generic environment of the Level II model can be compared to the calculated value for chlorobenzene. The MTBE input into water is significantly more sensitive to the 'mode of entry' than input into air. The MTBE concentration in surface water is almost exclusively the result of direct emission into water, whereas the atmosphere can additionally be loaded by volatilization from water. The total aquatic MTBE emission in Germany and the average MTBE concentration in German surface waters were roughly estimated to 20-80 t a(-1) (tons per year)(50 t a(-1)) and 50 ng L(-1), respectively. Surface water concentrations calculated with the underlying assumptions of the model can neither be explained by exposure through waste water and industrial effluents nor with an estimated loss of industrially used MTBE in Germany. For the year-round scenario at 10 degrees C, MTBE concentrations of 19 ng L(-1) (surface water) and 167 ng m(-3) (air) result. However, it remains unclear whether the assumptions of the model, the lack of analyses from industrial effluents or both are responsible for the difference. Additional aquatic emission sources could result from gasoline transport on and storage near rivers. The comparison of winter and summer scenarios shows that in summer, atmospheric (25%) and aqueous (50%) concentrations are lower than in winter due to higher degradation rates. 相似文献
347.
Our objectives were to measure concentrations of seven trace elements and 14 organochlorine compounds in sediment and biota of the shoalgrass (Halodule wrightii) community of the lower Laguna Madre of south Texas and to determine whether chemicals associated with agriculture (e.g. mercury, arsenic, selenium, organochlorine pesticides) were highest near agricultural drainages. Arsenic, mercury, selenium, lead, cadmium, and organochlorines were generally at background concentrations throughout the lower Laguna Madre. Nickel and chromium concentrations were exceptionally high in shrimp and pinfish (Lagodon rhomboides), which is difficult to explain because of no known anthropogenic sources for these trace elements. For sediment and blue crabs (Callinectes sapidus), mercury was highest near agricultural drainages. Also, DDE was more frequently detected in blue crabs near agricultural drainages than farther away. In contrast, selenium concentrations did not differ among collecting sites and arsenic concentrations were lowest in shoalgrass, blue crabs, and brown shrimp (Penaeus aztecus) near agricultural drainages. 相似文献
348.
Hecker Markus Hollert Henner Cooper Ralph Vinggaard Anne-Marie Akahori Yumi Murphy Margaret Nellemann Christine Higley Eric Newsted John Wu Rudolph Lam Paul Laskey John Buckalew Angela Grund Stefanie Nakai Makoto Timm Gary Giesy John 《Environmental science and pollution research international》2007,14(1):23-30
Background, Goals and Scope In response to concerns that have been raised about chemical substances that may alter the function of endocrine systems and
result in adverse effects on human health, an OECD initiative was undertaken to develop and validate in vitro and in vivo assays to identify chemicals that may interfere with endocrine systems of vertebrates. Here we report on studies that were
conducted to develop and standardize a cell-based screening assay using the H295R cell line to prioritize chemicals that may
act on steroidogenic processes in humans and wildlife. These studies are currently ongoing as part of the ‘Special Activity
on the Testing and Assessment of Endocrine Disruptors’ within the OECD Test Guidelines Program to review, develop, standardize,
and validate a number of in vitro and in vivo toxicological assays for testing and assessment of chemicals concerning their potential to interact with the endocrine system
of vertebrates.
Study Design Six laboratories from five countries participated in the pre-validation studies. Each laboratory tested the effects of three
model chemicals on the production of testosterone (T) and estradiol (E2) using the H295R Steroidogenesis Assay. Chemicals
tested were well described inducers or inhibitors of steroidogenic pathways (forskolin, prochloraz and fadrozole). All experiments
were conducted in 24 well plates following standard protocols. Six different doses per compound were analyzed in triplicate
per plate. A quality control (QC) plate was run in conjunction with the chemical exposure plate to account for inter-assay
variation. Each chemical exposure was conducted two or three times.
Results All laboratories successfully detected increases and/or decreases in hormone production by H295R cells after exposure to the
different model compounds and there was good agreement in the pattern of response for all groups. Forskolin increased both
T and E2 while fadrozole and prochloraz decreased production of both hormones. All chemicals affected hormone production in
a dose-dependent manner with the exception of fadrozole which caused maximum inhibition of E2 at the two least concentrations
tested. Some inter-laboratory differences were noted in the alteration of hormone production measured in chemically exposed
cells. However, with the exception of the production of T measured at one laboratory in cells exposed to forskolin, the EC50s calculated were comparable (coefficients of variation 34–49%) for all hormones.
Discussion and Perspectives The results indicated that the H295R Steroidogenesis Assay protocol was robust, transferable and reproducible among all laboratories.
However, in several instances that were primarily related to one laboratory there were unexplained minor uncertainties related
to the inter-laboratory hormone production variation. Based on the findings from this Phase 2 prevalidation study, the H295R
Steroidogenesis Assay protocol is currently being refined. The next phase of the OECD validation program will test the refined
protocol among the same group of laboratories using an extended set of chemicals (∼30) that will include positive and negative
chemical controls as well as a broad spectrum of different potential inducers and inhibitors of steroidogenic pathways.
Submission Editor: Dr. Carsten Brühl (bruehl@uni-landau.de) 相似文献
349.
David J. H. Brock David Bedgood Caroline Hayward Neil J. Carbarns Christine Gosden 《黑龙江环境通报》1984,4(4):261-266
Measurement of the microvillar enzymes, γ-glutamyltranspeptidase (GGTP), aminopeptidase M (APM) and alkaline phosphatase (ALP), in amniotic fluid supernatant has been proposed as a method for the early prenatal diagnosis of cystic fibrosis. The activities of these enzymes in a series of other fetal abnormalities have now been examined. GGTP activities were below the 5th percentile in 28 out of 54 cases of trisomy 21 and 9 of 14 cases of trisomy 18, while APM values were below this cut-off in 26 of 54 cases of trisomy 21 and 8 of 14 cases of trisomy 18. Abnormal ALP isoenzyme ratios were found in 6 of 54 cases of trisomy 21 and 4 of 14 cases of trisomy 18. If prenatal cytogenetic studies are routinely carried out on amniotic fluid cells, the occasional confounding effect of abnormal microvillar enzymes associated with fetal trisomies rather than with cystic fibrosis should be avoided. 相似文献
350.
Lisa Strain Mary E. M. Porteous Christine M. Gosden Patricia M. Ellis James P. Neilson David T. Bonthron 《黑龙江环境通报》1994,14(6):469-474
Direct detection of the fragile X mutation by DNA analysis has greatly simplified prenatal diagnosis of this disease. However, women carrying a fragile X premutation may pass their expanded trinucleotide repeat to sons without expansion to a full mutation. Such sons are predicted to be intellectually normal. In this situation, the accuracy with which the fetal status can be inferred from analysis of chorionic villus sample (CVS) DNA is unclear. We describe such a case, in which it was felt necessary to proceed to fetal blood sampling despite technically unambiguous DNA results from the CVS. The lack of prospective data means that this dilemma may be expected to recur over the next few years when performing prenatal diagnosis on fragile X premutation carriers. 相似文献