Chemistry. Soluble allotropes of main-group elements     

Dyker CA  Bertrand G 《Science (New York, N.Y.)》2008,321(5892):1050-1051

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Modelling the probability and impact of false-positive serology for Borrelia burgdorferi sensu lato: A case study     

Rosa M. A. C. Houben  Carole Meersschaert  Guy Hendrickx  Pierre-Hugues Pitel  Hélène Amory 《Equine veterinary journal》2021,53(1):71-77

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Purification of a Low Molecular Weight Fucoidan for SPECT Molecular Imaging of Myocardial Infarction     

Pierre Saboural  Frédéric Chaubet  Francois Rouzet  Faisal Al-Shoukr  Rana Ben Azzouna  Nadia Bouchemal  Luc Picton  Liliane Louedec  Murielle Maire  Lydia Rolland  Guy Potier  Dominique Le Guludec  Didier Letourneur  Cédric Chauvierre 《Marine drugs》2014,12(9):4851-4867

Fucoidans constitute a large family of sulfated polysaccharides with several biochemical properties. A commercial fucoidan from brown algae, containing low molecular weight polysaccharidic species constituted of l-fucose, uronic acids and sulfate groups, was simply treated here with calcium acetate solution. This treatment led to a purified fraction with a yield of 45%. The physicochemical characterizations of the purified fucoidan using colorimetric assay, MALLS, dRI, FT-IR, NMR, exhibited molecular weight distributions and chemical profiles similar for both fucoidans whereas the sulfate and l-fucose contents increased by 16% and 71%, respectively. The biodistribution study in rat of both compounds labeled with ^99mTc evidenced a predominant renal elimination of the purified fucoidan, but the crude fucoidan was mainly retained in liver and spleen. In rat myocardial ischemia-reperfusion, we then demonstrated the better efficiency of the purified fucoidan. This purified sulfated polysaccharide appears promising for the development of molecular imaging in acute coronary syndrome.  相似文献   

Effects of genetic strain and holding facility on the characteristics of alkaline phosphatase and brush border enzymes in silver perch (Bidyanus bidyanus)     

Yaniv Hakim  Stuart J Rowland  Jeff A Guy  Charles Mifsud  Zehava Uni  & Sheenan Harpaz 《Aquaculture Research》2007,38(4):361-372

The activity of the enzymes located in the digestive tract (pyloric caeca and intestine) in two strains and F₁ crosses of the Australian freshwater fish silver perch [Murray River (M) and Cataract Dam (C)] was evaluated. The effect of the fish holding system (cages or ponds) on the activity of alkaline phosphatase (AP) and the brush border enzymes: maltase, leucine amino peptidase (LAP) and γ‐glutamyl transferase (γ‐GT) was examined. The enzymatic activity was tested in three intestinal sections: the pyloric caeca, upper and lower intestine. All the tested enzyme activities were influenced by an interaction between the intestinal section and the strain or cross of silver perch. For fish maintained in ponds, there were two distinct enzymatic activity patterns, one for the pure strains (C × C and M × M) and one for the crosses (C × M and M × C). Significantly higher (P<0.05) enzymatic activities of the crosses compared with the pure strains were particularly noticeable in the pyloric caeca. In fish held in cages, there was a significantly higher (P<0.05) enzymatic activity in the pyloric caeca of the C × C strain. The total enzymatic activities in the fish reared in the ponds were significantly higher (P<0.05) than those in the fish held in cages. The results of the present investigation confirm that the different genetic background of the silver perch in the Murray River and in the Cataract Dam influences the activity of the brush border digestive enzymes. This activity also varies between maintenance systems.  相似文献   

Influence of tropical seasonal changes on oocyte diameter, responses to hormonal induction and hatching quality in two strains of the catfish, Heterobranchus longifilis Val. (Clariidae)     

David Nguenga  Guy G Teugels  Marc Legendre  & Frans Ollevier 《Aquaculture Research》2004,35(14):1349-1357

A comparison was made between the oocyte diameter, pseudo‐absolute fecundity (PAF) and egg quality of two strains of the catfish, Heterobranchus longifilis, maintained in outdoor ponds under a tropical highland climate in Cameroon. The results indicated that circannual endogenous rhythms for ovarian recrudescence and regression are absent in H. longifilis, irrespective of breeding history, age and strain. There appeared to be a possible slight adverse effect of climate (dry season) on reproductive performance of both strains. Oocyte diameter and PAF increased with increasing fish weight when data from both strains were combined, indicating that the two strains may exhibit the same reproductive performance. Viable eggs were obtained all year round after hormonal induction. It is concluded that for propagation of H. longifilis in tropical African countries, broodfish could be maintained in outdoor earthen fish ponds with proper feeding.  相似文献   

A simple method for the evaluation of red clover (Trifolium pratense L.) resistance to Sclerotinia trifoliorum     

Bertrand Delclos  Claire Mousset-Déclas  Guy Raynal 《Euphytica》1997,93(2):173-179

Sclerotinia crown and stem rot is the most destructive disease on red clover in areas with cool seasons including North America and Europe. An artificial inoculation test in controlled conditions has been developed in order to evaluate resistance to this fungus in individual plants. Measured drops of ascospore suspension were applied to detached clover leaflets and disease severity scored on a visual scale. Clovers from 16 cultivars and 12 ecotypes were tested for resistance to Sclerotinia trifoliorum. The results obtained for cultivar resistance are in agreement with those of other tests described in the literature. Moreover, repeated individual evaluations on detached leaflets from the same plant was successful in detecting genotypic variation within clover populations.  相似文献   

Genotypic lipoxygenase variation in soybean seeds and response to nitrogen nutrition     

A. Zougari    S. Guy  C. Planchon 《Plant Breeding》1995,114(4):313-316

Decreasing the lipoxygenase content of soybean (Glycine max (L.) Merr.) seed is a prerequisite for its increased use in human foods. These investigations aim to analyse the variation of lipoxygenase contents in relation to the genotype or the nitrogen nutrition of the plant. Four genotypes from a divergent selection for N₂ fixation and the recurrent parent, Weber, were grown in pots, and two Bradyrhizobium japonicum strains (G.49 and SMGS1) were used. Dinitrogen fixation was estimated in situ using the acetylene–reduction assay. The lipoxygenase activity was determined polarographically on seeds taken from plants grown under controlled conditions in the presence or absence of symbiotic N₂ fixation. The large genotypic variation observed for the lipoxygenase contents was enhanced by high N₂ fixation. The variation range of lipoxygenase contents, which was obtained through the combination of the genotypic variation and the N₂ fixation activity, was relatively large with a ratio of 2 on a seed dry–weight basis and a ratio of 2.6 when the total proteins were considered. Decreased lipoxygenase content and increased total protein content can thus be considered in parallel in a genetic context, together with more efficient N₂ fixation.  相似文献   

Insect growth regulators as potential insecticides to control olive fruit fly (Bactrocera oleae Rossi): insect toxicity bioassays and molecular docking approach     

Paloma Bengochea  Olivier Christiaens  Fermín Amor  Elisa Viñuela  Pierre Rougé  Pilar Medina  Guy Smagghe 《Pest management science》2013,69(1):27-34

BACKGROUND: Olive fruit fly, Bactrocera oleae (Rossi), is a key pest in olive orchards, causing serious economic damage. To date, the pest has already developed resistance to the insecticides commonly applied to control it. Thus, in searching for new products for an accurate resistance management programme, targeting the ecdysone receptor (EcR) might provide alternative compounds for use in such programmes. RESULTS: Residual contact and oral exposure in the laboratory of B. oleae adults to the dibenzoylhydrazine‐based compounds methoxyfenozide, tebufenozide and RH‐5849 showed different results. Methoxyfenozide and tebufenozide did not provoke any negative effects on the adults, but RH‐5849 killed 98‐100% of the treated insects 15 days after treatment. The ligand‐binding domain (LBD) of the EcR of B. oleae (BoEcR‐LBD) was sequenced, and a homology protein model was constructed. Owing to a restricted extent of the ligand‐binding cavity of the BoEcR‐LBD, docking experiments with the three tested insecticides showed a severe steric clash in the case of methoxyfenozide and tebufenozide, while this was not the case with RH‐5849. CONCLUSION: IGR molecules similar to the RH‐5849 molecule, and different from methoxyfenozide and tebufenozide, might have potential in controlling this pest. Copyright © 2012 Society of Chemical Industry  相似文献   

Spatial road disturbance index (SPROADI) for conservation planning: a novel landscape index, demonstrated for the State of Brandenburg, Germany     

Lisa Freudenberger  Peter R. Hobson  Slaven Rupic  Guy Pe’er  Martin Schluck  Julia Sauermann  Stefan Kreft  Nuria Selva  Pierre L. Ibisch 《Landscape Ecology》2013,28(7):1353-1369

The expansion of roads, and the subsequent changes to the surrounding landscape not only lead to landscape fragmentation but also have been shown to be a key driver of biodiversity loss and ecosystem degradation. Local declines of species abundance as well as changes in animal behaviour have drawn attention to wider ecosystem effects including altered species composition and a degradation of ecosystem functioning. However, methods for measuring and quantifying the distribution and environmental impacts of roads are not yet fully developed. We present a new technique for assessing the potential impacts of roads on biodiversity using a spatial road disturbance index (SPROADI). The index is calculated from three sub-indices: traffic intensity as a measure of traffic volume per time and space; vicinity impact, which is the assessment of edge effect of roads on adjacent habitats (the road-effect zone); and fragmentation grade, which provides an indication of the degree to which the landscape is intersected by roads. SPROADI was then tested using data from the Federal State of Brandenburg in north-eastern Germany. A sensitivity analysis was carried out on the results to assess the robustness of the index. The findings revealed expected patterns of high road disturbance in urban and peri-urban landscapes surrounding Berlin. Less obvious were the high levels of road density and impacts in forest plantations across the southern region of Brandenburg, and low levels of road disturbance in agricultural crop lands of the north-western region. Results were variable for areas under some form of protection. The only national park displayed substantially lower SPROADI values in contrast to the surrounding non-protected areas whilst other protected area categories, which were landscape conservation areas and nature parks, revealed SPROADI values that were equally high as those for non-protected areas. The results of this study demonstrate the strengths and potential applications of SPROADI as a quantitative means for identifying low-traffic areas in the context of conservation and sustainable transport planning.  相似文献   

Enset (Ensete ventricosum) clone selection by farmers and their cultural practices in southern Ethiopia     

Zerihun Yemataw  Hussein Mohamed  Mulugeta Diro  Temesgen Addis  Guy Blomme 《Genetic Resources and Crop Evolution》2014,61(6):1091-1104

Enset, Ensete ventricosum, is a crop that contributes to food security for more than 20 % of Ethiopia’s population. One clone never fulfills all the ecological and social requirements and hence farmers maintain a diverse range of enset cultivars on their farm. The objective of this work was to assess morphological and use value related characterization and document the indigenous knowledge of farmers on classification, cultivation and utilization of enset. A total of 280 farm households in seven zones were surveyed using individual household interviews. The observed traits showed low to high levels of variability among enset clones with a Shannon–Weaver diversity index (H′) value of 0.154–0.827 for bulla (extracted starch) quality and midrib color, respectively. Moreover, the overall H′ mean of 0.399 confirmed the existence of low to medium levels of phenotypic variation. The mean squares due to genotypes were highly significant (P ≤ 0.01) for all the quantitative traits studied, suggesting the presence of substantial genetic variability among the 165 enset clones. Kocho (fermented starch) yield had significant positive correlation with bulla quality and plant vigor. Knowledge of farmers’ practices is currently used to validate agronomic innovations and inform the setting up of a network of phenotype collections managed by farmers.  相似文献