Sporulation patterns in<i>Botrytis cinerea</i>

Background and Aims The presence of viable sources and of conditions favourable for conidial production, dispersal and deposition is essential for a high number of Botrytis cinerea conidia to be available at host infection sites. This study investigated the effect of environmental conditions, growing media and grape organs on the sporulation of ten strains of different genotypes and geographical origin. Method and Results Media of different water activity and similar to berry juice at several maturity stages, grape bunch trash or mature berries were inoculated with B. cinerea and incubated under variable conditions of temperature and relative humidity. Optimal conditions for sporulation were: temperature between 15 and 20°C, relative humidity >65.5%; water activity=0.971; and medium similar to the juice of softening berries. Conidia produced on bunch trash and mature berries were significantly correlated with those on artificial media. Conclusions Differences among strains did not change the response pattern of sporulation to the environmental conditions. Equations were then developed for describing the effect of temperature and relative humidity on sporulation, and of degree-days on the length of latent period. Significance of the Study When combined with predictive models for infection, our equations could contribute to the development of an effective disease prediction system for Botrytis bunch rot

Analytical Models Synthesis of Power Electronic Converters

In this paper we proposes a synthesis of different mathematical models of power electronic converters based on Thevenin/Norton equivalent circuits. Those models, composed by impedances and harmonic noise sources, are helpful to predict the conducted ElectroMagnetic Interferences (EMI) generated by converters connected to the electrical network. Moreover, the extracted impedances are determining for sizing EMC filters. The proposed analytical model is tested with PSpice simulations and validated by experimental measurements, from DC frequency until 30MHz

Comparison of efficacy and modes of action of two high-potential biocontrol Bacillus strains and commercial biocontrol products against Botrytis cinerea in table grapes

In table grapes (cv. Thomson Seedless), the antifungal activity against Botrytis cinerea was further analysed and compared between two high potential bacterial biological control agent (BCA) strains, Bacillus velezensis BUZ-14 and B. ginsengihumi S38. Two commercial biocontrol products (BPs), served as standards of comparison, Amylo-X (R) and Serenade Max (R), also based on Bacillus BCA strains. The main mode of action quantified for all the strains was antibiosis due to hydrosoluble and volatile metabolites and their combinations. The BUZ-14 strain was the most active BCA strain, demonstrating significant disease reduction exceeding 60 % when used in the culture form grown in 863 medium, including living cells (LCs) and cell-free supernatant (CFS). Both BPs exhibited significantly reduced efficacy of their CFS fraction (< 10 %) compared with that of the two BCA strains, confirming their high antibiosis potential. The novel methodology allowed us to demonstrate the significant effect of the BCA culture medium on volatilome (VOC) antagonist efficacy. The S38 strain achieved the highest disease reduction (90 %) owing to the greatest production of VOCs in the richest MOLP (Medium Optimum Lipopetide Production) culture medium, whereas grape juice was the least favourable medium for VOC efficacy for both bacterial strains (BUZ14 and S38). The overall poor activity of living Bacillus cells in all the BCA and BPs tested is discussed based on the low capacity of the BCA strains to grow in the berry. Then, the presence of living cells is also discussed with the possibility that these cells are not required in field applications of such BCA strains in this genus. Moreover, different environmental suboptimal conditions, including temperature (22 and 27 degrees C) and relative humidity (RH) (100 and 85-95 %), were tested, and BUZ-14 exhibited the highest Botrytis reduction at both temperatures and RH values. However, no significant differences were observed between temperatures or RH values for the same BCA. Further studies in vineyard conditions and applications, such as biofumigation or active packaging, will be performed to confirm the new findings reported in this investigation

A new integrative assessment indicator for damage caused by major pests and diseases in the vineyard

An original and integrative evaluation indicator has been developed to quantify the cumulated damage from major pests and diseases affecting grape bunches: downy mildew, powdery mildew, gray mould and tortricid moths. It made it possible to estimate the associated crop losses and to relate them to the plant protection strategy in different modes of production (organic farming, in-transition, conventional). Thus, overall plant losses were higher in 2012 than in 2011. The in-transition growers’ strategy, with reduced copper doses but increased numbers of sprays, led to a 20% increase in average severity on bunches (essentially due to Downy mildew). The more pragmatic approach of experienced organic growers and conventional ones (higher doses and fewer sprays) reduced the yield losses. The proposed indicator is used for two purposes, i) evaluating the quantitative losses due to pest attacks and ii) differentiating them from other non-pest ones. A more detailed analysis including the impact on performance will be achieved and published soon

Health Education Program on Stress Management for High School Students

The purpose of this study was to develop a health education program on stress management for high school students. In this program, we intended students to understand the effects of stressors on their mental and physical health, to be aware of their own stress and coping patterns, and to cope and behave in more improved manners. Learning activities in this program consist of brain storming, mapping of stress coping, drawing their own profiles of stressors, stress coping, and stress responses, in which each student thinks, writes, draws, or acts by him-or herself. The effectiveness of our program would be evaluated with 3 scales developed by Lim (1996) : the cognitive stress scale, the stress coping scale, and the stress response scale. Finally, we noticed the importance of creating healthy environment as well as the health education we planned

New insight about the functionality of oenological tannins; Main results of the working group on oenological tannins

This communication synthetize all the results obtained by the OIV working group on oenological tannins to the current date. The obtained results confirm that oenological tannins really exert a protection effect against grape juice and wine oxidation because they have antioxidant activity, they consume directly oxygen and they exert an inhibitory effect on the laccase activity. Moreover, oenological tannins also exert a copigmentation effect which can improve and protect de color of red wines

Mixing in a swarm of bubbles rising in a confined cell measured by mean of PLIF with two different dyes

The present contribution reports an experimental study of the mixing of a passive scalar of very low diffusivity in a homogeneous swarm of inertial bubbles rising in a thin gap. A patch of fluorescent dye is injected within the swarm, and we observe the evolution of its mass in a given region of observation. We analyse the effect of the liquid agitation on the mixing mechanisms varying the gas volume fraction from 1.3 to 7.5 %, while the Reynolds number of the bubbles, Re = 450, their Weber number, We = 0.7, and the gapto-bubble diameter ratio, w/d = 0.25, are kept approximately constant. Here, the in-plane local mass of dye is measured by using a two-dyes planar laser-induced fluorescence (PLIF) technique that has been adapted to fix the problem of multiple light reflections at the bubble interfaces. Indeed, they induce both temporal and spatial variations of the captured light intensity that are superimposed to the effective fluorescence signal and prevent from using a standard PLIF technique. The analysis of the instantaneous concentration fields reveals the dominant role of the bubble wakes in the scalar transport. It is shown that mixing in this planar confined geometry is very efficient and enhanced by the increasing gas volume fraction. The present study also highlights that the mixing is not governed by a Fickian law of diffusion

Hydroxyapatite-TiO2-SiO2-Coated 316L Stainless Steel for Biomedical Application

This study investigated the effectiveness of titania (TiO2) as a reinforcing phase in the hydroxyapatite (HAP) coating and silica (SiO2) single-layer as a bond coat between the TiO2-reinforced hydroxyapatite (TiO2/HAP) top layer and 316L stainless steel (316L SS) substrate on the corrosion resistance and mechanical properties of the underlying 316L SS metallic implant. Single-layer of SiO2 film was first deposited on 316L SS substrate and studied separately. Water contact angle measurements, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectrophotometer analysis were used to evaluate the hydroxyl group reactivity at the SiO2 outer surface. The microstructural and morphological results showed that the reinforcement of HAP coating with TiO2 and SiO2 reduced the crystallite size and the roughness surface. Indeed, the deposition of 50 vol. % TiO2-reinforced hydroxyapatite layer enhanced the hardness and the elastic modulus of the HAP coating, the introduction of SiO2 inner-layer on the surface of the 316L SS allowed the improvement of the bonding strength and the corrosion resistance as confirmed by scratch studies, nanoindentation and cyclic voltammetry tests

Interaction puissance-commande au sein des convertisseurs statiques

The electrical energy conversion is increasingly conversion is increasingly used in actual electrical systems. Also, the reduction of energical losses during the energy conversion has become an important objective. Thus, the electronic switch speed has been increased and allowed to reduce losses, but the technological implantation of components induces some electromagnetic compatibility problems. This is the reason of the interest of static converter designers in the Electromagnetic Compatibility. So, the study concerns the different risks of static converter malfunctioning due to its technology. Connections between energical sources (receiver and transmitter) and electronic switches (power unit and control unit) are often constituted of printed circuit traces, wires and copper bars. This connection is not perfect and its parasitic elements can disturb the static converter, even sometimes until its malfunctioning. The proposed study remains qualitative and unfolds in two times. In a first time, malfunctioning causes are shown according to the technology. For each case, risks are evaluated and design rules outlined. In a second time, proposed rules are applied onh a power static DC/DC converter, allowing to improve layout forward a better operating safety.Dans les systèmes électriques actuels, l'électronique de puissance est de plus en plus utilisée pour conditionner l'énergie électrique. Les convertisseurs statiques ont subi une évolution technologique importante notamment pour augmenter leur rendement et leur compacité. Ces performances sont essentiellemnt dues à l'accroissement de la rapidité des interrupteurs électroniques qui permert une réduction des pertes par commutation (absence de circuit d'aide à la commutation) et l'apparition de techniques de câblage nouvelles (hybrides, SMI...). Cependant, l'implantation technologique de ces composants modernes n'est pas sans poser quelques problèmes de compatibilité électromagnétique (perturbations de l'environnement, autoperturbation). La conception moderne de convertisseurs statiques ne permet plus d'ignorer les principes et les règles élémentaires de compatibilité électromagnétique (CEM) que ce soit dans la phase d'élaboration de prototype ou de préindustrialisation. C'est pourquoi les concepteurs de convertisseurs statiques s'intéressent à la Compatibilité Électromagnétique de leurs systèmes. De façon plus concrète, l'objectif de cet article est d'étudier les risques de dysfonctionnement des convertisseurs statiques dus à leur conception technologique. Les liaisons entre les sources d'énergie via les interrupteurs électroniques (de puissance et de commande) constituent ce que nous appelons la connectique. Le plus souvent, cette connectique est constituée de pistes de circuit imprimé, de fils ou encore de barres massives en cuivre ou aluminium. Cette connectique ne peut plus être considérée comme idéale étant donné les fréquences ou les grandeurs (fréquence, ${\rm d}I/{\rm d}t$, ${\rm d}V/{\rm d}t$) qui y transitent. Ses éléments parasites peuvent provoquer des troubles graves au sein du convertisseur statique allant même parfois jusqu'à son dysfonctionnement. L'étude proposée se déroule en deux temps. Dans un premier temps, les causes de dysfonctionnement sont mises en évidence et ordonnées en fonction de la technologie. Pour chaque cas, les risques sont évalués et des règles de conception ébauchées. Dans un deuxième temps, les règles proposées sont appliquées à un hacheur et sa commande et permettent de faire évoluer la conception du système vers une meilleure sûreté de fonctionnement