Search

– The aim of EU-project "Seed Treatments for Organic Vegetable Production" (STOVE) was to evaluate non-chemical methods for control of seed-borne pathogens in organic vegetable production. Physical (hot air, hot water and electron) and biologi-cal (microorganisms and different agents of natural origin) methods have been investigated. Trials have been carried out with different patho-systems such as cabbage / Alternaria spp and parsley / Septoria pet-roselini. Good control was generally obtained with the physical methods. In field trials, the yield of parsley naturally infested by S. petroselini was increased by 20 % when the seeds were treated with hot air. In trials performed under controlled conditions, also thyme oil treatment increased the number of germinated seedlings of this crop compared to the untreated control. Treatments with different commercialised microbial preparations reduced incidence of disease caused by Alternaria spp. in cabbage seedlings to a level similar to that achieved after chemical treatment. Many of the non-commercialised microoganisms also reduced disease incidence clearly.

– Production of pathogen-free seeds is a major goal in organic farming. In the framework of the EU-funded project “STOVE” (“Seed Treatments for Organic Vegetable Production”) physical and biological methods of seed treatment (alone and in combination) were investigated in different vegetable / pathogen systems. Overall, the physical treatments (hot water, hot air and electron treatment) resulted in a moderate to good control of the respective diseases. Also, from all biological treatment groups (microorganisms, plant extracts and inducers of resistance) candidates with promising control properties could be identified. The influence of the biological methods on emergence was often more prominent under greenhouse than under field conditions. The efficacy of given single and combined treatments depended strongly on the host / pathogen system investigated. Moreover, it turned out that the cultivar and also the seed lot differed to a large extent with respect to their sensitivity, so that selection of treatment parameters need to be considered thoroughly for each vegetable species and seed lot

Physical sanitation methods are used by the seed industry to prevent transmission of seed-borne diseases, but sensitivity varies between seed lots. The effect of seed maturity on the sensitivity to hot water, aerated steam and electron treatments was studied. Two Brassica oleracea L. and two Daucus carota L. seed lots from commercial production were selected for containing relatively large amounts of less mature seeds. Each seed lot was sorted into three maturity fractions based on the levels of chlorophyll fluorescence of individual seeds. Less mature B. oleracea and D. carota seeds were more susceptible to hot water treatments and less mature B. oleracea seeds to the aerated steam treatment. Seed maturity did not influence the sensitivity to the applied electron seed treatments. Seed lots were not selected for infections with seed-borne pathogens, however the less mature seeds were observed to be more frequently infected. It would be advisable to harvest seeds as mature as possible and to remove less mature seeds during seed processing. Sorting seeds by their level of chlorophyll fluorescence provides a useful method of sorting B. oleracea and D. carota seed lots. This would result in more efficient physical sanitation of seed lots

Although very often cited in publications dealing with food products, electronic noses still pose metrology problems. Lack of reproducibility is one of the more crucial problems, prohibiting any on-line quality control measurement based on an aroma reference previously taken. The database drift is due either to the intrinsic drift of the sensor or to the variations of experimental conditions. In order to quantify the influence of these conditions on the sensor performance, three screening experimental designs were performed on standard conditions, containing wine off-flavour volatiles. Three parameters were studied : the head-space temperature, the cell temperature, and the way of injecting samples. Their influence on indexes representing repeatability and discrimination allowed the determination of the best experimental set-up., Bien que très souvent cité dans la littérature concernant les produits alimentaires, les nez électroniques posent encore des problèmes de métrologie. Le manque de reproductibilité est l`un des problèmes les plus cruciaux, gênant toute mesure en ligne de la qualité à partir d'une odeur préalablement référencée. La dérive de la base de données est due soit à la dérive intrinsèque du capteur, soit aux variations de conditions expérimentales. Afin de quantifier l'influence de ces conditions sur la performance des capteurs, trois configurations expérimentales ont été réalisées avec des solutions modèles contenant des défauts d'arômes viniques. Trois paramètres ont été étudiés : la température de l'espace de tête, la température de la chambre de mesure, et la manière d'injecter les échantillons. Leur influence sur les indices traduisant la répétabilité et la discrimination ont permis l'identification des meilleures conditions expérimentales.

Although very often cited in publications dealing with food products, electronic noses still pose many problems. One is the extraction of features from the response curve ; in general, only the adsorption maximum is retained and input into a classification system. This paper describes a statistic-based methodology developed to extract the most pertinent features from the outputs of SnO2-gas sensor array. Several features are extracted from each sensor curve and also from its primary and secondary derivatives. They are then sorted, taking into account three specific indexes, designed to describe the repeatability, discrimination power and their redundancy. To generalise this approach, the acquisitions are carried out using various operating conditions. This protocol is applied to set of model mixtures, representing wine with satisfactory and unsatisfactory tart or vinegar flavour. This paper shows that relevant information can be obtained from the curve maximum, but also from features related to derivaties. Moreover, the most efficient features are the same for the five sensors, which would seem to indicate that they should also be the most suitable ones for all Sn02 sensors., Bien que souvent cités dans les publications traitant de produits alimentaires, les nez électroniques posent encore de nombreux problèmes. L'un d'eux est l'extraction de critères à partir des courbes de réponse des capteurs ; en général, seul le maximum de la phase d'adsorption est retenu dans la courbe et intégré à un système de classification. Cette publication décrit une méthodologie basée sur les statistiques pour extraire les critères les plus pertinents en sortie des barrettes de détecteurs de gaz à semi-conducteurs. Plusieurs critères ont été extraits de la courbe de chaque capteur ainsi que des dérivées première et seconde de chaque courbe. Ils ont été ensuite triés, en prenant en compte trois indices spécifiques conçus pour décrire la répétabilité, le pouvoir de discrimination, et la redondance. Pour généraliser cette approche, les acquisitions sont faites en utilisant diverses conditions opératoires. Ce protocole est appliqué pour un ensemble de mélanges de solutions, modélisant du vin avec ou sans des défauts olfactifs de type piqué ou oxydé. Cette publication montre qu'une information pertinente peut être obtenue à partir du maximum des courbes, mais aussi à partir de critères issus de la dérivée des courbes de signaux. De plus, les critères les plus efficaces sont les mêmes pour les cinq capteurs, ce qui semblerait indiquer qu'ils seraient les plus adaptés pour tout capteur Sn02.

Chloroquine can prevent photosensitivity reactions, but its mechanism of action is poorly understood. To investigate if the drug may interfere with inflammatory or immunological mechanisms of the UV-induced erythema of photosensitive patients, we studied the localization of chloroquine in the skin and its effect on the epidermal/dermal expression of IL-1, TNF-alpha, IL-6 and ICAM-1 and the occurrence of different lymphoid cells in normal skin and UVB-induced erythema in 8 patients with photosensitive discoid and systemic lupus erythematosus and 4 patients with polymorphic light eruption (PMLE), before and during chloroquine treatment. Using a specific monoclonal antibody against chloroquine, we found a strong granular staining pattern of mainly keratinocytes in all biopsy specimens from normal and erythematous skin during chloroquine treatment. In non-irradiated skin, T lymphocytes, macrophages and HLA-DR expressing cells were sparsely distributed within the dermis in similar amounts before and during chloroquine treatment. In UVB-induced erythema an increase in the number of these cells, mainly located in the dermal perivascular area, was seen before medication. During chloroquine treatment such cellular infiltration was reduced. ICAM-1 expression was detected on the endothelium of dermal vessels but not on keratinocytes. The accumulation of chloroquine in the epidermis and the decreased cellular infiltration in erythematous skin during chloroquine treatment indicate a local anti-inflammatory effect. This effect may be due to either unspecific UV-protective properties of the drug or to some specific downregulating action by chloroquine on keratinocyte function