Activité antifongique in vitro du phoséthyl-Al sur quelques souches de Verticillium albo-atrum Reinke & Berthold

La fongitoxicité du phosphonate, métabolite actif du phoséthyl-Al est modulée par la composition des milieux de culture. Sur le Cristomalt (milieu naturel) la toxicité du phosphonate vis-à-vis du Verticillium albo-atrum Reinke & Berthold. fonne à microsclérotes. est beaucoup plus grande que sur le Ribeiro (milieu synthétique). L'addition du phosphate au milieu de culture abaisse l'efficacité du phosphonate. Ce sont toujours les souches de Verticillium pathogènes sur la tomate, qui sont les plus sensibles au phoséthyl-Al.In vitro antifungal activity of fosetyl-Al on several strains of Verticillium albo-alrum Reinloe & BertholdToxicity of phosphonate, the active breakdown product of the fosethyl-Al, is modulated by culture media composition. On the Cristomalt ( natural medium), phosphonate toxicity against Verticillium albo-atrum Reinke & Berthold,-microsclerotial fonn, is higher than in synthetic media (Ribeiro). Phosphate is the main constituent of culture medium which modifies phosphonate fungitoxicity. Strains ofVerticillium, pathogenicon tomato, are al ways more sensitive" to fosethyl-Al

Microstructure and crystallographic properties of Cu77Zn21 alloy under the effect of heat treatment

International audienceThe influence of heat treatment process on microstructure and physiochemical properties of Cu77Zn21 alloy was studied. Samples were heated from 300 to 700°C for 15 minutes and gradually cooled to room temperature. Samples were characterized using mechanical testing and surface analysis techniques. It was observed that the grain size increases with the increasing temperature. The decrease in hardness is due to composition change of the Cu-Zn alloy attributed to zinc diffusion.XRD shows the presence of only α brass with a preferential orientation along the (111) plane. The analyses show that temperature affects the crystalline parameters. The rms microstrain was reduced mainly by thermal activation. The heat treatment promotes atomic diffusion and leads to a better crystallinity of the particles. The results of Raman investigations confirmed the changes in the Cu-Zn alloy surface composition with a clear enrichment in CuO. This behavior correlates with the results obtained by mechanical testing. © 2018, © 2018 Informa UK Limited, trading as Taylor and Francis Group

Microstructure and crystallographic properties of Cu77Zn21 alloy under the effect of heat treatment

The influence of heat treatment process on microstructure and physiochemical properties of Cu77Zn21 alloy was studied. Samples were heated from 300 to 700°C for 15 minutes and gradually cooled to room temperature. Samples were characterized using mechanical testing and surface analysis techniques. It was observed that the grain size increases with the increasing temperature. The decrease in hardness is due to composition change of the Cu-Zn alloy attributed to zinc diffusion.XRD shows the presence of only α brass with a preferential orientation along the (111) plane. The analyses show that temperature affects the crystalline parameters. The rms microstrain was reduced mainly by thermal activation. The heat treatment promotes atomic diffusion and leads to a better crystallinity of the particles. The results of Raman investigations confirmed the changes in the Cu-Zn alloy surface composition with a clear enrichment in CuO. This behavior correlates with the results obtained by mechanical testing. © 2018, © 2018 Informa UK Limited, trading as Taylor and Francis Group

Characterization of Tunisian genetic resources of Watermelon (Citrullus lanatus)

In Tunisia, watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] is largely consumed in summer as a fresh fruit. This cucurbit is cultivated in various areas in the country. The landraces are a very important source of genetic diversity, constituting an important genetic resource for plant breeders. The aim of the present study was to collect and characterize fruit diversity of watermelon landraces collected from local farmers from Monastir and Sousse areas of Tunisia. The landraces were categorized for 20 variables of fruit features according to UPOV descriptors for watermelon. Also, these landraces were screened by artificial inoculation for their resistance to Fusarium oxysporun f.sp niveum (FON) races 0 and 2 to identify sources of resistance to Fusarium wilt. Significant differences were found among accessions for the quantitative traits recorded, revealing a large diversity. The evaluated watermelon landraces expressed a wide range of phenotypes including fruit size, flesh color, rind pattern, FON disease resistance and sweetness.Publishe

Methodology for evaluating and comparing flow cytometers: A multisite study of 23 instruments

We demonstrate improved methods for making valid and accurate comparisons of fluorescence measurement capabilities among instruments tested at different sites and times. We designed a suite of measurements and automated data processing methods to obtain consistent objective results and applied them to a selection of 23 instruments at nine sites to provide a range of instruments as well as multiple instances of similar instruments. As far as we know, this study represents the most accurate methods and results so far demonstrated for this purpose. The first component of the study reporting improved methods for photoelectron scale (Spe) evaluations, which was published previously (Parks, El Khettabi, Chase, Hoffman, Perfetto, Spidlen, Wood, Moore, and Brinkman: Cytometry A 91 (2017) 232-249). Those results which were within themselves are not sufficient for instrument comparisons, so here, we use the Spe scale results for the 23 cytometers and combine them with additional information from the analysis suite to obtain the metrics actually needed for instrument evaluations and comparisons. We adopted what we call the 2+2SD limit of resolution as a maximally informative metric, for evaluating and comparing dye measurement sensitivity among different instruments and measurement channels. Our results demonstrate substantial differences among different classes of instruments in both dye response and detection sensitivity and some surprisingly large differences among similar instruments, even among instruments with nominally identical configurations. On some instruments, we detected defective measurement channels needing service. The system can be applied in shared resource laboratories and other facilities as an aspect of quality assurance, and accurate instrument comparisons can be valuable for selecting instruments for particular purposes and for making informed instrument acquisition decisions. An institutionally supported program could serve the cytometry community by facilitating access to materials, and analysis and maintaining an archive of results. © 2018 International Society for Advancement of Cytometry