11 research outputs found
Development and validation of a gas chromatography-mass spectrometry method for determining acaricides in bee pollen
ProducciĂłn CientĂficaPesticides can be found in beehives for several reasons, including contamination from surrounding crops or for their use by beekeepers, which poses a risk to bee ecosystems and consumers. Therefore, efficient and sensitive methods are needed for determining pesticide residues in bee products. In this study, a new analytical method has been developed and validated to determine seven acaricides (atrazine, chlorpyrifos, chlorfenvinphos, α-endosulfan, bromopropylate, coumaphos, and Ï-fluvalinate) in bee pollen using gas chromatography coupled to mass spectrometry. After an optimization study, the best sample treatment was obtained when using a modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method employing an ethyl acetate and cyclohexane as the extractant mixture, and a mixture of salts for the clean-up step. A chromatographic analysis (<21 min) was performed in an Agilent DB-5MS column, and it was operated under programmed temperature conditions. The method was fully validated in terms of selectivity, limits of detection (0.2â3.1 ”g kgâ1) and quantification (0.6â9.7 ”g kgâ1), linearity, matrix effect (<20% in all cases), trueness (recoveries between 80% and 108%), and precision. Finally, the proposed method was applied to analyze commercial bee pollen samples, and some of the target pesticides (chlorfenvinphos, α-endosulfan, coumaphos, and Ï-fluvalinate) were detected.Instituto Nacional de InvestigaciĂłn y TecnologĂa Agraria y Alimentaria (INIA) y Fondo Europeo de Desarrollo Regional (FEDER) - (grant RTA2017-00004-C02-0
Les récits historiques entre Orient et Occident, XIe-XVe siÚcle
Espace privilĂ©giĂ© dâĂ©changes et de circulation, la MĂ©diterranĂ©e mĂ©diĂ©vale est un thĂ©Ăątre de rencontres entre chrĂ©tiens dâOrient et dâOccident. Celles-ci constituent un moyen de transmission des savoirs et des connaissances, elles contribuent Ă façonner de nouvelles reprĂ©sentations tant sur le plan de lâhistoire que sur le plan des espaces ou de lâecclĂ©siologie. Les conditions de production de textes historiques, leur circulation, leurs usages et lâautoritĂ© qui leur est confĂ©rĂ©e permettent alors dâexaminer comment Latins, Grecs et Orientaux tiennent compte de lâaltĂ©ritĂ© interne ou externe Ă la chrĂ©tientĂ© dans sa dĂ©finition mĂȘme. La quĂȘte des origines, le plus souvent destinĂ©e Ă fonder une autoritĂ©, peut ainsi ĂȘtre mise au service tantĂŽt dâune rĂ©flexion critique sur la situation prĂ©sente, tantĂŽt dâune stratĂ©gie de lĂ©gitimation dâune entreprise Ă venir. CentrĂ© sur lâOccident et les Orients chrĂ©tiens, de Constantinople Ă lâĂthiopie en passant par lâArmĂ©nie, cet ouvrage nâen porte pas moins sur une aire rĂ©gionale mĂ©diterranĂ©enne oĂč, Ă lâexception de sa partie nord-occidentale, les pouvoirs islamiques gagnent en importance au dĂ©triment des pouvoirs chrĂ©tiens. Entre Occident et Orients chrĂ©tiens, ilkhanides et islamiques, porositĂ©, emprunts ou, Ă lâinverse, revendications identitaires de communautĂ©s qui, loin de vivre isolĂ©es les unes des autres, sont en interaction constante, constituent une variable supplĂ©mentaire de la dĂ©finition dâune Ă©criture de lâhistoire. Ce livre offre une rĂ©flexion transversale autour de la production et de la transmission des rĂ©cits historiques dans lâespace mĂ©diterranĂ©en et proche-oriental au Moyen Ăge. Ces rĂ©cits sont autant de symptĂŽmes de lâintĂ©gration constante quâopĂšrent des sociĂ©tĂ©s interconnectĂ©es et ouvertes Ă de nouveaux espaces comme Ă lâintroduction de nouvelles idĂ©es
A dual role of dLsd1 in oogenesis: regulating developmental genes and repressing transposons
International audienc
Revisiting the calculation of performance margins in monitoring-enabled optical networks
Modeling Protein Destiny in Developing Fruit
Protein synthesis and degradation are essential processes that regulate cell status. Because labeling in bulky organs, such as fruits, is difficult, we developed a modeling approach to study protein turnover at the global scale in developing tomato (Solanum lycopersicum) fruit. Quantitative data were collected for transcripts and proteins during fruit development. Clustering analysis showed smaller changes in protein abundance compared to mRNA abundance. Furthermore, protein and transcript abundance were poorly correlated, and the coefficient of correlation decreased during fruit development and ripening, with transcript levels decreasing more than protein levels. A mathematical model with one ordinary differential equation was used to estimate translation (kt) and degradation (kd) rate constants for almost 2,400 detected transcript-protein pairs and was satisfactorily fitted for over a thousand pairs. The model predicted median values of about 2 min for the translation of a protein, and a protein lifetime of approximately 11 days. The constants were validated and inspected for biological relevance. Proteins involved in protein synthesis had higher kt and kd values, indicating that the protein machinery is particularly flexible. Our model also predicts that protein concentration is more strongly affected by the rate of translation than that of degradation
Le cimetiĂšre dâAtlit, un espace des morts au pied de ChĂąteau-PĂšlerin (royaume latin de JĂ©rusalem - XIIIe siĂšcle)
Sur la cĂŽte israĂ©lienne, le cimetiĂšre dâAtlit est implantĂ© Ă quelques centaines de mĂštres de ChĂąteau PĂšlerin et dâun bourg Ă©difiĂ©s Ă partir de 1217-1219. DĂ©couvert en 1934, il revĂȘt un caractĂšre exceptionnel : avec plus de 1 900 tombes installĂ©es sur quatre-vingts ans, il est le plus grand ensemble sĂ©pulcral conservĂ© du royaume latin de JĂ©rusalem. Sa mise en place et son utilisation se situent au moment dâintensescontacts entre lâOrient et lâOccident. Quâil sâagisse de pĂšlerins ou de colons, il convient alors de sâinterroger sur la maniĂšre dont les chrĂ©tiens latins ont enterrĂ© leurs morts. Ă ce titre, les vivants procĂšdent-ils exactement comme en Occident ? Le « modĂšle cimĂ©tĂ©rial » et les rites funĂ©raires ont-ils Ă©tĂ© exportĂ©s et/ou adaptĂ©s ? Est-il possible dâidentifier dâĂ©ventuelles interactions avec les coutumes des populationslocales ? Face Ă des questions restĂ©es en suspens, une Ă©quipe internationale a mis en place une Ă©tude interdisciplinaire de grande ampleur. Lâapplication des mĂ©thodes dĂ©veloppĂ©es en archĂ©ologie funĂ©raire et en anthropologie biologique a alors permis dâanalyser lâorganisation du site, les pratiques funĂ©raires et lâidentitĂ© des inhumĂ©s. En combinant des investigations de terrain et des Ă©tudes de sources Ă©crites, lesrĂ©flexions centrĂ©es sur les liens entre les vivants et les morts placent aujourdâhui le cimetiĂšre dâAtlit dans des thĂ©matiques dâoccupation du sol, tout autant que dans celles dĂ©diĂ©es aux marqueurs spatiaux de mĂ©moire et dâidentitĂ©.The Atlit Cemetery on the Israeli coast was situated a few hundred meters from the ChĂąteau-PĂšlerin and near a small town which was built from 1217-1219. It was discovered in 1934 and is exceptional in character. It has more than 1900 tombs spread over an eighty-year period and is thus the largest grouping of tombs that has been preserved from the Latin Kingdom of Jerusalem. It was established and used at a time of intense contact between East and West. This is a good place to examine how the Latin Christiansâboth pilgrims and colonistsâburied their dead. Did the living proceed exactly as they did in the West? Were the âmodel cemeteryâ and the funeral rites exported and/or adapted? Is it possible to identify any interactions with the customs of the local people? In order to deal with these unresolved questions an international team undertook awide-ranging interdisciplinary study. Methods developed in Funerary Archaeology and Biological Anthropology were used to analyze the organization of the site, the funerary practices and the identities of the occupants of the graves. By combining field work with the study of the written sources our study of the relationship between the living and the dead allows us to see the Atlit Cemetery today in terms of the occupation of the ground as well as with reference to the spatial markers of memory and Identity