Propriétés insecticides de Chenopodium ambrosoides et Tephrosia vogelii vers la bruche de l'arachide Caryedon serratus

L'efficacité de poudres de #Tephrosia vogelii (une source connue de roténone) et de cinq autres plantes utilisées traditionnellement au Congo pour la protection des stocks contre les insectes, a été évaluée. A la dose de 1 pour 40, #Chenopodium ambrosioides et #Tephrosia vogelii affectent la survie des adultes de #Caryedon serratus : 90,0 et 98,8 %, respectivement, meurent au bout de 13 jours. Le nombre d'oeufs pondus est très faible ou nul. Les autres plantes n'ont aucun effet ou un effet mineur sur les différents stades de l'insecte. (Résumé d'auteur

Les problèmes de conservation du manioc en cossettes au Congo

Une liste est fournie des insectes infestant les cossettes de manioc séchées au Congo. Au total, 12 espèces de coléoptères nuisibles ont été identifiées ; la plus nuisible est #Araecerus fasciculatus$. (Résumé d'auteur

Механизмы образования мишенных инсерций при синтезе молекулы ДНК, содержащей цис-син циклобутановые цитозиновые димеры

В рамках развиваемой полимеразно-таутомерной модели ультрафиолетового мутагенеза предлагается модель механизма образования мишенных инсерций, вызванных цис-син циклобутановыми цитозиновыми димерами. Инсерции — это мутации сдвига рамки чтения, когда встраивается одно или несколько оснований ДНК. Структурный анализ встраивания оснований показал, что напротив двух редких таутомерных форм цитозина невозможно встроить ни одно из канонических оснований так, чтобы между ними и матричными основаниями образовались водородные связи. Поэтому при синтезе молекулы ДНК, содержащей цис-син циклобутановые цитозиновые димеры, содержащие молекулы цитозина в таких редких таутомерных формах, специализированные или модифицированные ДНК-полимеразы напротив этих цис-син циклобутановых цитозиновых димеров будут оставлять бреши в один нуклеотид. На участках ДНК с однородным нуклеотидным составом, в соответствии с моделью Стрейзингера, конец нити ДНК может сползти, соединиться с помощью водородных связей так, что образуется петля. В результате дочерняя нить удлиняется, появляется мишенная мутация сдвига рамки чтения — мишенная инсерция.У рамках розроблюваної полiмеразно-таутомерної моделi ультрафiолетового мутагенезу, запропоновано модель механiзму формування мiшенних iнсерцiй, що викликанi цис-син циклобутановими цитозиновими димерами. Iнсерцiї — це мутацiї зсуву рамки читання, коли вбудовується одна або декiлька основ ДНК. Структурний аналiз вбудовування основ показав, що навпроти двох рiдких таутомерних станiв цитозину неможливо вбудувати жодну з канонiчних основ так, щоб мiж ними та матричними основами сформувались водневi зв’язки. Тому при синтезi молекули ДНК, що мiстить цис-син циклобутановi цитозиновi димери, що мають молекули цитозину в таких рiдких таутомерних формах, спецiалiзованi або модифiкованi ДНК-полiмерази навпроти цих цис-син циклобутанових цитозинових димерiв будуть залишати проломи в один нуклеотид. На дiлянках ДНК з однорiдним нуклеотидним складом, вiдповiдно до моделi Стрейзингера, кiнець нитки ДНК може сповзти, з’єднатися за допомогою водневих зв’язкiв так, що утвориться петля. У результатi подовжується дочiрня нитка, з’являється мiшенна мутацiя зсуву рамки читання — мiшенна iнсерцiя.A polymerase — tautomer model of ultraviolet mutagenesis is developed. The mechanism of formation of targeted insertions that is caused by cis-syn cyclobutane cytosine dimers is proposed. Insertions are frameshift mutations, when one or several DNA bases are inserted. Structural analysis has shown that, opposite two rare tautomeric forms of cytosine, it is impossible to insert any canonical DNA bases with template bases with the formation of hydrogen bonds. Therefore, under the synthesis of DNA containing cis-syn cyclobutane cytosine dimers with cytosine molecules in such rare tautomeric forms, specialized or modified DNA polymerases will leave one nucleotide gaps opposite these cis-syn cyclobutane cytosine dimers. On DNA sites with homogeneous nucleotide composition, the end of a DNA strand may slip and join with hydrogen bonds so that a loop is formed by the Streisinger model. As a result, the daughter strand is elongated, and the targeted insertion is formed

Comparative Testing Report on the Detection and Quantification of Maize Event MON 810 - Comparative testing round: ILC-CRL-GMFF-CT-02/10

In the frame of Regulation (EC) No 882/2004, the European Union Reference Laboratory for Genetically Modified Food and Feed has the duty to organise comparative testing rounds and to ensure an appropriate follow-up of these activities. This report describes the outcome of the second comparative testing round ILC-CRL-GMFF-CT-02/10. Participants had to determine the GM content in two test items denoted maize powder levels 1 and 2, containing different GM percentages of maize event MON 810. This comparative testing round was organised in collaboration with the Reference Materials Unit and the Food Safety and Quality Unit of the Institute for Reference Materials and Measurements (Geel, BE). The maize event MON 810 test items were produced by the Reference Materials Unit. The Food Safety and Quality Unit managed the on-line registration and submission of results. A total of 136 laboratories were invited to participate in ILC-CRL-GMFF-CT-02/10. Six National Reference Laboratories declined participation, of which two were no longer a National Reference Laboratory. Ninety laboratories from 41 countries returned results, of which 65 were National Reference Laboratories, six were members of the European Network of GMO Laboratories only and 19 were laboratories from third countries. Two National Reference Laboratories, two Official control laboratories and nine laboratories from a third country did not submit any results. Participants could report the results of the exercise either in mass/mass % or in copy/copy %. The outcome of this second comparative testing round was in general positive, with 82-100 % of participants gaining a z-score in the range of -2 to +2 for both maize powder levels 1 and 2 regardless of the calibration method, the measurement unit and the approach used for calculating the z-score.JRC.I.3-Molecular Biology and Genomic

The GOODSTEP project: General Object-Oriented Database for Software Engineering Processes

The goal of the GOODSTEP project is to enhance and improve the functionality of a fully object-oriented database management system to yield a platform suited for applications such as software development environments (SDEs). The baseline of the project is the O2 database management system (DBMS). The O2 DBMS already includes many of the features regulated by SDEs. The project has identified enhancements to O2 in order to make it a real software engineering DBMS. These enhancements are essentially upgrades of the existing O2 functionality, and hence require relatively easy extensions to the O2 system. They have been developed in the early stages of the project and are now exploited and validated by a number of software engineering tools built on top of the enhanced O2 DBMS. To ease tool construction, the GOODSTEP platform encompasses tool generation capabilities which allow for generation of integrated graphical and textual tools from high-level specifications. In addition, the GOODSTEP platform provides a software process toolset which enables modeling, analysis and enaction of software processes and is also built on top of the extended O2 database. The GOODSTEP platform is to be validated using two CASE studies carried out to develop an airline application and a business application

Hull Consistency Under Monotonicity

International audienceWe prove that hull consistency for a system of equations or inequalities can be achieved in polynomial time providing that the underlying functions are monotone with respect to each variable. This result holds including when variables have multiple occurrences in the expressions of the functions, which is usually a pitfall for interval-based contractors. For a given constraint, an optimal contractor can thus be enforced quickly under monotonicity and the practical significance of this theoretical result is illustrated on a simple example

Hematological variations in healthy participants exposed 2 h to propylene glycol ethers under controlled conditions.

Glycol ethers are solvents used in a plethora of occupational and household products exposing the users to potential toxic effects. Several glycol ethers derived from ethylene glycol induce hematological toxicity, such as anemia in workers. The exposure effects on blood cells of glycol ethers derived from propylene glycol are unknown in humans. The aim of our study was to evaluate blood parameters indicative of red blood cell (RBC) hemolysis and oxidative stress in participants exposed to propylene glycol (propylene glycol monobutyl ether (PGBE) and propylene glycol monomethyl ether (PGME)), two extensively used propylene glycol derivatives worldwide. Seventeen participants were exposed 2 h in a control inhalation exposure chamber to low PGME (35 ppm) and PGBE (15 ppm) air concentrations. Blood was regularly collected before, during (15, 30, 60, and 120 min), and 60 min after exposure for RBC and oxidative stress analyses. Urine was also collected for clinical effects related to hemolysis. Under the study conditions, our results showed that the blood parameters such as RBCs, hemoglobin concentration, and white blood cells tended to increase in response to PGME and PGBE exposures. These results raise questions about the possible effects in people regularly exposed to higher concentrations, such as workers

HtrA1 Mediated Intracellular Effects on Tubulin Using a Polarized RPE Disease Model

Age-related macular degeneration (AMD) is the leading cause of irreversible vision loss. The protein HtrA1 is enriched in retinal pigment epithelial (RPE) cells isolated from AMD patients and in drusen deposits. However, it is poorly understood how increased levels of HtrA1 affect the physiological function of the RPE at the intracellular level. Here, we developed hfRPE (human fetal retinal pigment epithelial) cell culture model where cells fully differentiated into a polarized functional monolayer. In this model, we fine-tuned the cellular levels of HtrA1 by targeted overexpression. Our data show that HtrA1 enzymatic activity leads to intracellular degradation of tubulin with a corresponding reduction in the number of microtubules, and consequently to an altered mechanical cell phenotype. HtrA1 overexpression further leads to impaired apical processes and decreased phagocytosis, an essential function for photoreceptor survival. These cellular alterations correlate with the AMD phenotype and thus highlight HtrA1 as an intracellular target for therapeutic interventions towards AMD treatment

Pentamidine Dosage: A Base/Salt Confusion

Pentamidine has a long history in the treatment of human African trypanosomiasis (HAT) and leishmaniasis. Early guidelines on the dosage of pentamidine were based on the base-moiety of the two different formulations available. Confusion on the dosage of pentamidine arose from a different labelling of the two available products, either based on the salt or base moiety available in the preparation. We provide an overview of the various guidelines concerning HAT and leishmaniasis over the past decades and show the confusion in the calculation of the dosage of pentamidine in these guidelines and the subsequent published reports on clinical trials and reviews. At present, only pentamidine isethionate is available, but the advised dosage for HAT and leishmaniasis is (historically) based on the amount of pentamidine base. In the treatment of leishmaniasis this is probably resulting in a subtherapeutic treatment. There is thus a need for a new, more transparent and concise guideline concerning the dosage of pentamidine, at least in the treatment of HAT and leishmaniasi