The influence of environmental factors on the upstream movements of rheophilic cyprinids according to their position in a river basin          下载免费PDF全文

Jean‐Philippe Benitez  Michaël Ovidio 《Ecology of Freshwater Fish》2018,27(3):660-671

Throughout their lives, fish accomplish frequent movements between functional habitats that are often triggered by environmental signals. We aimed to determine if rheophilic cyprinids (barbel, Barbus barbus and chub Squalius cephalus), living in different places of the same river basin, may develop similar movement periodicities and react identically to environmental cues to carry out their spawning migration. We used the capture data of three modern fish passes that were monitored continuously during three consecutive years (2010 to 2012) in three rivers of the Meuse basin in Belgium. We captured 418 individuals at adult stage, and the capture number per species was greater (80%) in spring (during the spawning migration period). The spawning migration of the barbel occurred earlier (median = 122nd day of the year) and at lower temperatures (median = 14.5°C) in the lowland rivers compared to the upland river (140th day of the year and 18.4°C). For the barbel, migration initiation differed depending on the river but finished under similar environmental conditions. In contrast, for the chub, no significant difference between rivers was observed regarding spawning migration periodicity and environmental cues. Within the same river basin, rheophilic cyprinids demonstrate flexibility in their responses to environmental variables and may optimise the start date of migration to spawning grounds depending on their local environment and individual experiences. This phenomenon was more pronounced in the barbel, which has more specific ecological requirements.  相似文献   

Evaluation of antibody-ELISA and real-time RT-PCR for the diagnosis and profiling of bluetongue virus serotype 8 during the epidemic in Belgium in 2006   总被引：3，自引：0，他引：3  

Vandenbussche F  Vanbinst T  Verheyden B  Van Dessel W  Demeestere L  Houdart P  Bertels G  Praet N  Berkvens D  Mintiens K  Goris N  De Clercq K 《Veterinary microbiology》2008,129(1-2):15-27

In 2006 bluetongue (BT) emerged for the first time in North-Western Europe. Reliable diagnostic tools are essential in controlling BT but data on the diagnostic sensitivity (Se) and specificity (Sp) are often missing. This paper aims to describe and analyse the results obtained with the diagnostics used in Belgium during the 2006 BT crisis. The diagnosis was based on a combination of antibody detection (competitive ELISA, cELISA) and viral RNA detection by real-time RT-PCR (RT-qPCR). The performance of the cELISA as a diagnostic tool was assessed on field results obtained during the epidemic and previous surveillance campaigns. As the infectious status of the animals is unknown during an epidemic, a Bayesian analysis was performed. Both assays were found to be equally specific (RT-qPCR: 98.5%; cELISA: 98.2%) while the diagnostic sensitivity of the RT-qPCR (99.5%) was superior to that of the cELISA (87.8%). The assumption of RT-qPCR as standard of comparison during the bluetongue virus (BTV) epidemic proved valid based on the results of the Bayesian analysis. A ROC analysis of the cELISA, using RT-qPCR as standard of comparison, showed that the cut-off point with the highest accuracy occurred at a percentage negativity of 66, which is markedly higher than the cut-off proposed by the manufacturer. The analysis of the results was further extended to serological and molecular profiling and the possible use of profiling as a rapid epidemiological marker of the BTV in-field situation was assessed. A comparison of the serological profiles obtained before, during and at the end of the Belgian epidemic clearly showed the existence of an intermediate zone which appears soon after BTV (re)enters the population. The appearance or disappearance of this intermediate zone is correlated with virus circulation and provides valuable information, which would be entirely overlooked if only positive and negative results were considered.  相似文献   

Measures for interoperability of phenotypic data: minimum information requirements and formatting     

Hanna??wiek-Kupczyńska  Thomas?Altmann  Daniel?Arend  Elizabeth?Arnaud  Dijun?Chen  Guillaume?Cornut  Fabio?Fiorani  Wojciech?Frohmberg  Astrid?Junker  Christian?Klukas  Matthias?Lange  Cezary?Mazurek  Anahita?Nafissi  Pascal?Neveu  Jan?van?Oeveren  Cyril?Pommier  Hendrik?Poorter  Philippe?Rocca-Serra  Susanna-Assunta?Sansone  Uwe?Scholz  Marco?van?Schriek  ümit?Seren  Bj?rn?Usadel  Stephan?Weise  Paul?Kersey  Pawe??KrajewskiEmail author 《Plant methods》2016,12(1):44

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Reducing flood risk from sediment-laden agricultural runoff using intercrop management techniques in northern France     

Philippe Martin   《Soil & Tillage Research》1999,52(3-4):233-245

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Phenotypic indicators for cultured pearl size improvement in the black‐lipped pearl oyster (Pinctada margaritifera): towards selection for the recipient growth performance          下载免费PDF全文

Chin‐Long Ky  Philippe Cabral  Cédrik Lo 《Aquaculture Research》2017,48(8):4132-4142

The black‐lipped pearl oyster, Pinctada margaritifera, is the most important farmed species in French Polynesia and the basis of the most valuable export industry. Mass production of black pearls relies on a surgical operation requiring tissue from a donor pearl oyster to be grafted, together with a nucleus made of shell, into the gonad of a recipient oyster. Improving pearl size through family selection remains one of the main challenges for future aquaculture development. This study analyses the relative contribution of donor and recipient oysters to pearl size. To this end, hatchery‐produced donor oysters of two batches, large and small (based on shell height), were used to supply grafts for recipients, which were then monitored individually for their growth performance by recording shell height, width, and thickness, and total live weight (flesh + shells) every 6 months (four biometric measurement times) over 20 months of culture. Pearls issued from the two batches of donors showed no significant differences in nacre weight or thickness. In contrast, recipient oyster shell height and total weight were increasingly positively correlated with these pearl size parameters over the culture period, becoming significant at 8 months post‐grafting. Potential therefore exists to use shell height and oyster weight as phenotypic indicators for selective breeding of recipient oysters with high growth performance to increase pearl size in P. margaritifera.  相似文献   

Fungal biodegradation of a phenylurea herbicide,diuron : structure and toxicity of metabolites     

Cline Tixier  Philippe Bogaerts  Martine Sancelme  Frdrique Bonnemoy  Landoald Twagilimana  Annie Cuer  Jacques Bohatier  Henri Veschambre 《Pest management science》2000,56(5):455-462

Microbial degradation, organic synthesis and ecotoxicology were used to investigate the fate of diuron after spreading on soils. Quantitative biodegradation assays were performed with fungal strains, showing that diuron was degraded but not entirely mineralized. The modifications observed consisted in demethylation of the terminal nitrogen atom. The identified metabolites were synthesized in sufficient amounts to confirm their structures and determine their non‐target toxicity using four biotests. The two metabolites exhibited higher effects than parent diuron. This limited biodegradability and potential aquatic toxicity suggest that diuron is of higher environmental concern than previously recognized. © 2000 Society of Chemical Industry  相似文献   

Is acetyl/butyrylcholine specificity a marker for insecticide‐resistance mutations in insect acetylcholinesterase?     

Franois Villatte  Philippe Ziliani  Sandino Estrada‐Mondaca  Philippe Menozzi  Didier Fournier 《Pest management science》2000,56(12):1023-1028

Substrate specificity has been widely studied in vertebrate cholinesterases and it has been shown that two phenylalanines in the acyl pocket of acetylcholinesterase govern the acceptance of the acetyl/butyryl moiety of the choline esters. As an insecticide‐resistance mutation has been evidenced in the acyl pocket of Drosophila melanogaster and Musca domestica acetylcholinesterase we investigated the possibility of linking changes in acetyl/butyrylthiocholine specificity with mutations in insect acetylcholinesterase. We thus analyzed the effect of 28 mutations in Drosophila enzyme on acetyl/butyrylthiocholine, N‐methyl/N‐propyl‐carbamates and ethyl/methyl‐paraoxon preference. It appeared that the highest changes on acetyl/butyrylthiocholine and N‐propyl/N‐methyl‐carbamates preference were due to mutations in the acyl pocket. Nevertheless, other insecticide‐resistance mutations, not located in the acyl pocket, also modified these substrate preferences. Moreover, the effect of mutations in the acyl pocket was hidden when some other insecticide‐resistance mutations were combined in the enzyme. Consequently, acetyl/butyrylthiocholine preference alteration cannot be used as a marker to localize a mutation in the insect AChE. © 2000 Society of Chemical Industry  相似文献   

Yield response of sugar beets to water stress under Western European conditions   总被引：1，自引：0，他引：1  

Nirman Shrestha  Dirk Raes  Sarah Soentjens  Philippe Clouet 《Agricultural Water Management》2010,97(2):346-1316

The average yield of sugar beet has almost doubled within the last 30 years. With the raise in average yields and the increase in sensitivity to water stress of sugar beets, the yield response factor (Ky) derived by Doorenbos and Kassam (1979) needs an update. In this article, the soil water balance model BUDGET (Raes et al., 2006) was calibrated and validated to obtain correct estimations of the evapotranspiration deficit (1 − ETa/ETc, where ETa = actual crop evapotranspiration and ETc = maximum crop evapotranspiration under standard conditions) of sugar beets in two locations in France. Datasets of observed soil water contents of several years and different irrigation treatments were used. The simulated evapotranspiration deficits and observed yields were used to derive a seasonal Ky. The obtained linear and polynomial yield response relation between observed yield decline and evapotranspiration deficit showed a high goodness-of-fit. The coefficient of determination (R²) = 0.83, the Nash-Sutcliffe efficiency (EF) = 0.79, the relative root mean squared error (RRMSE) = 0.26 for linear; the coefficient of determination (R²) = 0.85, the Nash-Sutcliffe efficiency (EF) = 0.79, the relative root mean squared error (RRMSE) = 0.25 for polynomial). The results suggested a more pronounced response of sugar beet to water stress in Europe as compared to the values previously reported by Doorenbos and Kassam (1979). The comparison between the observed and simulated yields (with the updated Ky) for another site in France confirmed the findings.  相似文献   

Macromolecular Features of Amaranth Starch     

Luis Arturo Bello-Prez  Paul Colonna  Philippe Roger  Octavio Paredes-Lpez 《Cereal Chemistry》1998,75(4):395-402

High-performance size-exclusion chromatography (HPSEC), static light scattering (SLS) and dynamic light scattering (DLS) techniques were used for the structural characterization of amaranth starch, solubilized in water by microwave heating in a high-pressure vessel. Apparent average molar mass (M _w) gyration radius (R _G), and hydrodynamic radius (R _H) values were obtained from Berry and Zimm treatment of light-scattering data. When heating time increased from 35 to 90 sec, the M _w, R _G, and R _H decreased, demonstrating a possible polymer degradation due to temperature. Apparent M _r values from HPSEC at 35 sec (27 ± 2 × 10⁷ g/mol) and 50 sec (20 ± 2 × 10⁷ g/mol) were lower than those determined by SLS (35 sec = 69 × 10⁷ g/mol, 50 sec = 56 × 10⁷ g/mol). However, at 70 and 90 sec, the inverse pattern was obtained. The fractal dimensions (d′_f) from HPSEC study for samples dissolved for 35 (3.26), 50 (3.24), and 70 sec (3.14) are characteristic of a particle that has the internal structure of hard sphere, and for samples dissolved for 90 sec (2.19), are characteristic of a fully swollen, randomly branched macromolecule. From SLS, d′_f decreased with increasing treatment time (d′_f = 2.44, 2.18, 1.50, and 1.03 for 35, 50, 70, and 90 sec, respectively). The particle-scattering factors and Kratky plots, well-suited for studying the internal structure of a macromolecule, showed a sample degradation when treatment time increased. Results from DLS showed bimodal distributions with differences in the peak locations when treatment time increased. The ratio of R _G to R _H (ρ) for samples analyzed were between 0.88 and 1.3; these values are characteristic of a sphere or globular structure.  相似文献   

An unexpected host for the endangered giant freshwater pearl mussel Margaritifera auricularia (Spengler, 1793) as a conservation tool     

Joaquín Soler  Catherine Boisneau  Philippe Jug  Nina Richard  Yann Guerez  Laure Morisseau  Karl Matthias Wantzen  Rafael Araujo 《水产资源保护:海洋与淡水生态系统》2019,29(10):1758-1770