Reduced cadherin expression associated with resistance to Bt toxin Cry1Ac in pink bollworm     

Jeffrey A Fabrick  Lolita G Mathew  Dannialle M LeRoy  J Joe Hull  Gopalan C Unnithan  Alex J Yelich  Yves Carrire  Xianchun Li  Bruce E Tabashnik 《Pest management science》2020,76(1):67-74

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3D fluorescent in situ hybridization using Arabidopsis leaf cryosections and isolated nuclei     

Leïla Tirichine  Philippe Andrey  Eric Biot  Yves Maurin  Valérie Gaudin 《Plant methods》2009,5(1):11-7

Background  

Fluorescent hybridization techniques are widely used to study the functional organization of different compartments within the mammalian nucleus. However, few examples of such studies are known in the plant kingdom. Indeed, preservation of nuclei 3D structure, which is required for nuclear organization studies, is difficult to fulfill.  相似文献   

Osmotic adaptation of Oncorhynchus kisutch Walbaum     

Gilles Boeuf  Pierre Lasserre  Yves Harache 《Aquaculture (Amsterdam, Netherlands)》1978,15(1):35-52

Coho salmon yearlings, reared in France in a freshwater hatchery, were directly transferred to sea water at three different periods of the year: 14 January, 3 March and 14 April 1976. The last two experiments were realized at three different salinities: 25, 30 and 35‰.The results show important seasonal differences in the osmoregulatory responses. The direct transfer to 35‰ reveals some osmoregulatory problems which are not discernable at lower salinities. Yearlings transferred to a 35‰ sea water present a much higher and faster rise of plasma electrolytes and of branchial Na⁺K⁺ ATPase activity than fish transferred to a 25 or 30‰ sea water.It was found that a physiologically pre-adapted fish, characterized by a high level of branchial Na⁺K⁺ ATPase activity in fresh water (April) will present in sea water a slower and more regular increase in gill Na⁺K⁺ ATPase activity than fish with a low level of enzyme activity in fresh water (January–March). These smolts transferred to 25 and 30‰ sea water in April do not exhibit important variations, whereas a well-marked osmotic disequilibrium appears at 35‰. However, this osmotic stress is much more rapidly controlled than in the previous transfers.Our results suggest that the highest tolerance to sea water is reached only at time of smolting and that the time of transfer may have a direct influence on the intensity of the osmotic stress. These facts might be of considerable importance for the development of marine rearing of coho salmon in coastal areas where the salinities stay usually above 30‰ which constitutes an unusual environment for the species under consideration.  相似文献   

中华蜜蜂幼虫信息素鉴定   总被引：5，自引：2，他引：5  

颜伟玉  Yves LE CONTE  曾志将 《中国农业科学》2009,42(6):2250-2254

 【目的】分析鉴定中华蜜蜂(Apis cerana cerana)幼虫是否含有与西方蜜蜂（Apis mellifera）幼虫相同的幼虫利它素和信息素及其在不同日龄阶段幼虫的分布情况。【方法】以中华蜜蜂为试验材料,取2日龄、6日龄（即将封盖）和7日龄（封盖后）的工蜂幼虫及2日龄、7日龄（即将封盖）和8日龄（封盖后）的雄蜂幼虫,经过正己烷浸泡碾碎,取上清液并进行层析过柱分离,应用气相色谱来研究中华蜜蜂幼虫利它素和信息素。【结果】本研究首次发现中华蜜蜂幼虫信息素含有甲基棕榈酸酯（MP）、甲基油酸酯(（MO）、甲基硬脂酸酯（MS）、甲基亚油酸酯（ML）、甲基亚麻酸酯（MN）、乙基棕榈酸酯（EP）、乙基油酸酯（EO）、乙基硬脂酸酯（ES）、乙基亚油酸酯（EL）和乙基亚麻酸酯（EN）。【结论】中华蜜蜂幼虫含有与西方蜜蜂幼虫相同的幼虫利它素和10种脂肪类信息素,但这两种蜜蜂信息素的含量及在不同日龄幼虫分布规律不同。  相似文献   

Fingerprinting sediment sources in the outlet reservoir of a hilly cultivated catchment in Tunisia   总被引：1，自引：1，他引：1  

Abir Ben Slimane  Damien Raclot  Olivier Evrard  Mustapha Sanaa  Irène Lefèvre  Mehdi Ahmadi  Mouna Tounsi  Cornelia Rumpel  Abdallah Ben Mammou  Yves Le Bissonnais 《Journal of Soils and Sediments》2013,13(4):801-815

Purpose

Approximately 74 % of agricultural soils in Tunisia are affected by water erosion, leading to the siltation of numerous human-made reservoirs and therefore a loss of water storage capacity. The objective of this study was to propose a methodology for estimating the relative contributions of gully/channel bank erosion and surface topsoil erosion to the sediment accumulated in small reservoirs.

Materials and methods

We tested an approach based on the sediment fingerprinting technique for sediments collected from a reservoir (which has been in operation since 1994) at the outlet of a catchment (Kamech, 2.63 km²). Sampling concentrated on the soil surface (in both cropland and grassland), gullies and channel banks. A total of 17 sediment cores were collected along a longitudinal transect of the Kamech reservoir to investigate the origin of the sediment throughout the reservoir. Radionuclides (particularly caesium-137, ¹³⁷Cs) and nutrients (total phosphorus, total nitrogen and total organic carbon (TOC)) were analysed as potential tracers.

Results and discussion

The applications of a mixing model with ¹³⁷Cs alone or ¹³⁷Cs and TOC provided very similar results: The dominant source of sediment was surface erosion, which was responsible for 80 % of the total erosion within the Kamech catchment. Additionally, we showed that the analysis of a single composite core provided information on the sediment origin that was consistent with the analysis of all sediment layers in the core. We demonstrated the importance of the core sampling location within the reservoir for obtaining reliable information regarding sediment sources and the dominant erosion processes.

Conclusions

The dominance of surface erosion processes indicates that conservation farming practices are required to mitigate erosion in the agricultural Kamech catchment. Based on the results from 17 sediment cores, guidelines regarding the number and location of sampling cores to be collected for sediment fingerprinting are proposed. We showed that the collection of two cores limited the sediment source apportionment uncertainty due to the core sampling scheme to <10 %.  相似文献   

Acrylamide in French fries: influence of free amino acids and sugars   总被引：8，自引：0，他引：8  

Becalski A  Lau BP  Lewis D  Seaman SW  Hayward S  Sahagian M  Ramesh M  Leclerc Y 《Journal of agricultural and food chemistry》2004,52(12):3801-3806

The free amino acid profile and sugar (fructose, glucose, and sucrose) composition were determined in potato samples selected to give a large range of variation (a total of 66 samples). From these samples French fries were produced in a laboratory-scale simulation of an industrial process followed by a finish fry at 180 degrees C for 3.5 min using a restaurant fryer. The final product was blast frozen and analyzed for acrylamide. Acrylamide was detected in all samples, but its concentration varied significantly from 50 to 1800 ng/g. For isotope dilution (13C3) acrylamide analysis, samples were extracted with water, cleaned up on HLB Oasis polymeric and Accucat mixed mode anion and cation exchange SPE columns, and analyzed by LC-MS/MS. Statistical analysis of the data indicates that the effect of sugars and asparagine on the concentration of acrylamide in French fries is positive and significant (p < 0.001). It appears that one of the ways acrylamide formation in French fries can be effectively controlled is by the use of raw products with low sugar (and to a lesser degree, asparagine) content.  相似文献   

Quorum sensing as a target for developing control strategies for the plant pathogen <Emphasis Type="Italic">Pectobacterium</Emphasis>     

Denis Faure  Yves Dessaux 《European journal of plant pathology / European Foundation for Plant Pathology》2007,119(3):353-365

Quorum sensing is a regulatory mechanism that connects gene expression to cell density in bacteria. Amongst proteobacteria, numerous functions are regulated in this way, including pathogenicity in the Enterobacteriaceae genus Pectobacterium. In Pectobacterium, the signalling molecules involved in this regulatory process belong to the N-acyl-homoserine lactone class. Over the last 6 years, various studies have shown that these signal molecules could be degraded by other bacteria or by plant and animal cells, opening the path to innovative biocontrol strategies. This review explores the various determinants of pathogenicity in Pectobacterium and describes approaches that have been developed to quench the quorum-sensing-dependent pathogenicity in Pectobacterium. These approaches range from signal degradation by physicochemical constraints to the identification of signal-sensing inhibitors and from the identification of enzymes degrading acyl-homoserine lactones to the construction of transgenic plants tolerant to Pectobacterium.  相似文献   

Scale-dependent determinants of heterogeneity in fire frequency in a coniferous boreal forest of eastern Canada   总被引：1，自引：0，他引：1  

Dominic Cyr  Sylvie Gauthier  Yves Bergeron 《Landscape Ecology》2007,22(9):1325-1339

Despite the recognized importance of fire in North American boreal forests, the relative importance of stochastic and determinist portions of intra-regional spatial variability in fire frequency is still poorly understood. The first objective of this study is to identify sources of spatial variability in fire frequency in a landscape of eastern Quebec’s coniferous boreal forest. Broad-scale environmental factors considered included latitude, longitude, human activities and belonging to a given bioclimatic domain, whereas fine-scale factors included slope, position on the slope, aspect, elevation, surficial deposit and drainage. The average distance to waterbodies was also considered as a potential intermediate-scale source of variability in fire frequency. In order to assess these environmental factors’ potential influence, they were incorporated into a proportional hazard model, a semi-parametric form of survival analysis. We also used a digital elevation model in order to evaluate the dominant aspect within neighborhoods of varying sizes and successively incorporated these covariates into the proportional hazard model. We found that longitude significantly affects fire frequency, suggesting a maritime influence on fire frequency in this coastal landscape. We also found that position on the slope was related to fire frequency since hilltops and upperslopes were subject to a lower fire frequency. Dominant aspect was also related to fire frequency, but only when characterized within a neighborhood delimited by 4,000 to 10,000-m radii (5,027–31,416 ha). A 2–6-fold variation in fire frequency can be induced by geographic and topographic contexts, suggesting a substantial intra-regional heterogeneity in disturbance regime with potential consequences on forest dynamics and biodiversity patterns. Implications for forest management are also briefly discussed. Electronic supplementary material The online version of this article (doi: ) contains supplementary material, which is available to authorized users.  相似文献   

AFLP assessment of the genetic diversity of Calotropis procera (Apocynaceae) in the West Africa region (Benin)     

D. Angelo R. Agossou Yao  Yves Sprycha  Stefan Porembski  Renate Horn 《Genetic Resources and Crop Evolution》2015,62(6):863-878

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Inferences about the transmission of Schmallenberg virus within and between farms     

Simon Gubbins  Joanne Turner  Matthew Baylis  Yves van der Stede  Gerdien van Schaik  José Cortiñas Abrahantes  Anthony J. Wilson 《Preventive veterinary medicine》2014

In the summer of 2011 Schmallenberg virus (SBV), a Culicoides-borne orthobunyavirus, emerged in Germany and The Netherlands and subsequently spread across much of Europe. To draw inferences about the transmission of SBV we have developed two models to describe its spread within and between farms. The within-farm model was fitted to seroprevalence data for cattle and sheep farms in Belgium and The Netherlands, with parameters estimated using approximate Bayesian computation. Despite the short duration of viraemia in cattle and sheep (mean of 3–4 days) the within-farm seroprevalence can reach high levels (mean within-herd seroprevalence >80%), largely because the probability of transmission from host to vector is high (14%) and SBV is able to replicate quickly (0.03 per day-degree) and at relatively low temperatures (threshold for replication: 12.3 °C). Parameter estimates from the within-farm model were then used in a separate between-farm model to simulate the regional spread of SBV. This showed that the rapid spread of SBV at a regional level is primarily a consequence of the high probability of transmission from host to vector and the temperature requirements for virus replication. Our results, obtained for a region of the UK in a typical year with regard to animal movements, indicate that there is no need to invoke additional transmission mechanisms to explain the observed patterns of rapid spread of SBV in Europe. Moreover, the imposition of movement restrictions, even a total movement ban, has little effect on the spread of SBV at this scale.  相似文献