Antifungal activity and chemical composition of seven essential oils to control the main seedborne fungi of cucurbits

none9siEssential oils represent novel alternatives to application of synthetic fungicides to control against seedborne pathogens. This study investigated seven essential oils for in vitro growth inhibition of the main seedborne pathogens of cucurbits. Cymbopogon citratus essential oil completely inhibited mycelial growth of Stagonosporopsis cucurbitacearum and Alternaria alternata at 0.6 and 0.9 mg/mL, respectively. At 1 mg/mL, Lavandula dentata, Lavandula hybrida, Melaleuca alternifolia, Laurus nobilis, and two Origanum majorana essential oils inhibited mycelia growth of A. alternata by 54%, 71%, 68%, 36%, 90%, and 74%, respectively. S. cucurbitacearum mycelia growth was more sensitive to Lavandula essential oils, with inhibition of ~74% at 1 mg/mL. To determine the main compounds in these essential oils that might be responsible for this antifungal activity, they were analyzed by gas chromatography–mass spectrometry (GC-MS). C. citratus essential oil showed cirtal as its main constituent, while L. dentata and L. nobilis essential oils showed eucalyptol. The M. alternifolia and two O. majorana essential oils had terpinen-4-ol as the major constituent, while for L. hybrida essential oil, this was linalool. Thus, in vitro, these essential oils can inhibit the main seedborne fungi of cucurbits, with future in vivo studies now needed to confirm these activities.openMoumni M.; Romanazzi G.; Najar B.; Pistelli L.; Amara H.B.; Mezrioui K.; Karous O.; Chaieb I.; Allagui M.B.Moumni, M.; Romanazzi, G.; Najar, B.; Pistelli, L.; Amara, H. B.; Mezrioui, K.; Karous, O.; Chaieb, I.; Allagui, M. B

Facebook's Mobile Career

At the end of its first decade, Facebook’s identity, popularity, and characteristics are shaped in important ways by its becoming a form of mobile media, as much as it as platform associated with Internet and social media. This paper seeks to explore and understand Facebook as the important force in mobile media and communication it now is. It draws upon and combines perspectives from technology production, design, and economy, as well as user adoption, consumption, practices, affect, emotion, and resistance. The paper discusses the beginnings of mobile Facebook, and the early adoption of mobile Facebook associated with the rise of smartphones. The second part of the paper explores Facebook’s integration with photography (with Instagram) and social games (such as Zynga’s Farmville). The paper argues that Facebook’s mobile career is an accomplishment that has distinctively melded evolving affordances, everyday use across a wide range of settings, as well as political economies, corporate strategy, and design.Australian Research Counci

Wikipedia Arabe et la construction collective du savoir (Wikipedia Arabic and the collective construction of knowledge)

Cette recherche part du constat d’une faible participation à, et d’un maigre contenu dans Wikipedia Arabe et questionne les obstacles à un contenu plus riche. La problématique de la recherche est double: d’abord proposer une cartographie numérique de Wikipedia dans la région du Moyen-Orient et Afrique du Nord. Cette cartographie informe d’une part sur la représentation des participants à Wikipedia Arabe, et d’autre part, sur la contribution à la distribution du savoir arabe et de son étendue. Deuxièmement, la recherche s’intéresse au contenu de Wikipedia arabe et de son mode de production. Plus particulièrement, les questions de recherche portent sur la participation à la production de contenu de Wikipedia Arabe, les barrières à l’entrée dans Wikipedia Arabe, les dynamiques de négociation et de consensus entre éditeurs et administrateurs Wikipediens de la région et les solutions envisagées pour améliorer et encourager la production de contenu. La démarche méthodologique est principalement qualitative.So far Arabic content on Wikipedia Arabic is very weak; this paper questions the barriers that prevent contributors to Wikipedia Arabic from being more active in content production on Wikipedia Arabic. The research problematic is twofold: first, it suggests a digital cartography of Wikipedia in the MENA region that informs about those who represent Wikipedia Arabic and thus, contribute to the Arab knowledge distribution. Second, while adopting a qualitative approach, the research looks at the content of Arabic Wikipedia. It questions its production methods, contribution barriers, dynamics of negotiation between Wikipedians, and strategies of consensus between editors and admins, as well as the envisioned solutions to improve and promote Wikipedia Arabic content production.</p

Impact of dietary restriction on peroxidative effects of nickel chloride in wistar rats

International audienceThe purpose of this study, carried out in Wistar rats, was to evaluate the protective effect of dietary restriction (performed by intermittent fasting) against oxidative stress induced by a low concentration of nickel chloride in kidney, liver, uterus, and ovary. Lipid peroxidation (TBARS), catalase activity, and the levels of vitamins E and A in the blood were investigated in rats feed for 1 month either daily (N) or 1 day over two (intermittent fasting, IF) and then injected (NNi, IFNi) or not with nickel chloride (30 moles/kg body weight/day) for 10 days. Ni induced a significant increase of TBARS in organs of N rats. Intermittent fasting alone or associated to nickel treatment did not result in TBARS change in IF and IFNi rats. Catalase activity levels were found to be similar in N and IF rats. In Ni-treated rats a transient increase of catalase activity appeared at day 1 in the kidney and days 1 and 3 in the liver. Then, catalase activity was found to be inhibited until day 10. In the uterus and ovary, catalase activity was always found to be inhibited. In IFNi rats, no significant increase of catalase activity was observed as compared to IF rats. Vitamin E was inhibited from the 1st to the 10th day in Ni rats, whereas no significant changes were noted in IFNi rats. A moderate decrease of vitamin A was only found at days 1 and 3 in Ni rats. In conclusion, intermittent fasting is able to protect from oxidative stress induced by low concentration of Ni, but catalase and Vitamins E and A do not seem to be involved

Detection and Quantification of Stagonosporopsis cucurbitacearum in Seeds of Cucurbita maxima Using Droplet Digital Polymerase Chain Reaction

Stagonosporopsis cucurbitacearum is an important seedborne pathogen of squash (Cucurbita maxima). The aim of our work was to develop a rapid and sensitive diagnostic tool for detection and quantification of S. cucurbitacearum in squash seed samples, to be compared with blotter analysis, that is the current official seed test. In blotter analysis, 29 of 31 seed samples were identified as infected, with contamination from 1.5 to 65.4%. A new set of primers (DB1F/R) was validated in silico and in conventional, quantitative real-time PCR (qPCR) and droplet digital (dd) PCR. The limit of detection of S. cucurbitacearum DNA for conventional PCR was ∼1.82 × 10–2 ng, with 17 of 19 seed samples positive. The limit of detection for ddPCR was 3.6 × 10–3 ng, which corresponded to 0.2 copies/μl. Detection carried out with artificial samples revealed no interference in the absolute quantification when the seed samples were diluted to 20 ng. All seed samples that showed S. cucurbitacearum contamination in the blotter analysis were highly correlated with the absolute quantification of S. cucurbitacearum DNA (copies/μl) in ddPCR (R2 = 0.986; p ≤ 0.01). Our ddPCR protocol provided rapid detection and absolute quantification of S. cucurbitacearum, offering a useful support to the standard procedure